langfuse-mcp-java

Overview Schema Related Servers Score Discussions

Server Quality Checklist

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Latest release: v0.1.2
Disambiguation4/5
Most tools are clearly distinct by resource and action, such as create_annotation_queue vs. get_annotation_queue. However, some overlap exists in read operations like fetch_trace and get_exception_details, which both retrieve trace details but with different filters, potentially causing confusion. The descriptions help clarify, but the sheer number of tools (55) increases the risk of misselection.
Naming Consistency5/5
Tool names follow a highly consistent verb_noun pattern throughout, such as create_annotation_queue, get_annotation_queue, list_annotation_queues, and update_annotation_queue_item. All tools use snake_case without deviation, making the naming predictable and easy to understand. This consistency aids in agent navigation and reduces cognitive load.
Tool Count2/5
With 55 tools, the count is excessive for an MCP server, far beyond the typical well-scoped range of 3-15 tools. This large number suggests over-fragmentation, such as having separate tools for fetch_trace and get_exception_details, which could be consolidated. It will likely overwhelm agents and increase complexity unnecessarily.
Completeness5/5
The tool set provides comprehensive CRUD and lifecycle coverage for the Langfuse domain, including traces, sessions, datasets, prompts, models, scores, annotation queues, and LLM connections. There are no obvious gaps; every major resource has create, read, update, and delete operations, along with specialized tools for analytics and filtering, ensuring agents can handle full workflows without dead ends.
Average 3.2/5 across 55 of 55 tools scored. Lowest: 2.2/5.
See the Tool Scores section below for per-tool breakdowns.
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{
  "$schema": "https://glama.ai/mcp/schemas/server.json",
  "maintainers": [
    "your-github-username"
  ]
}
```
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How is the quality score calculated?

The overall quality score combines two components: Tool Definition Quality (70%) and Server Coherence (30%).

Tool Definition Quality measures how well each tool describes itself to AI agents. Every tool is scored 1–5 across six dimensions: Purpose Clarity (25%), Usage Guidelines (20%), Behavioral Transparency (20%), Parameter Semantics (15%), Conciseness & Structure (10%), and Contextual Completeness (10%). The server-level definition quality score is calculated as 60% mean TDQS + 40% minimum TDQS, so a single poorly described tool pulls the score down.

Server Coherence evaluates how well the tools work together as a set, scoring four dimensions equally: Disambiguation (can agents tell tools apart?), Naming Consistency, Tool Count Appropriateness, and Completeness (are there gaps in the tool surface?).

Tiers are derived from the overall score: A (≥3.5), B (≥3.0), C (≥2.0), D (≥1.0), F (<1.0). B and above is considered passing.

Tool Scores

Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Description claims 'Read-only' but annotations specify readOnlyHint=false and destructiveHint=true, indicating mutation/deletion capabilities. This is a dangerous contradiction. Description mentions pagination but fails to clarify destruction behavior that annotations indicate.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness3/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Brief two-sentence structure is appropriately concise, but both sentences contain inaccuracies (false optionality claim, read-only contradiction) that waste the agent's time and risk harmful invocations.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Missing output schema explanation (what session data returns?), no differentiation from similar list tools, and contains critical safety misinformation. Incomplete for a tool with destructive annotations that claims to be read-only.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema has 100% coverage (baseline 3), but description incorrectly characterizes timestamp parameters as 'optional' when schema marks them required. Mentions 'paginated' implying page/limit usage but doesn't add syntax guidance beyond schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose3/5
Does the description clearly state what the tool does and how it differs from similar tools?
States specific action (list) and resource (sessions) with scope details (paginated, time range). However, claims time range is 'optional' when schema marks timestamps as required, and fails to distinguish from sibling tools like get_session_details (singular) or get_user_sessions (user-scoped).
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Provides no guidance on when to use versus alternatives like get_session_details or get_user_sessions. No mention of prerequisites, authorization requirements, or when the time range filter is necessary versus fetching all sessions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description presents this as a read-only retrieval ('Returns...'), but annotations indicate destructiveHint=true and readOnlyHint=false, suggesting the tool modifies or deletes state. This is a direct contradiction. The description fails to explain what gets destroyed, why it is not idempotent, or the implications of openWorldHint=true.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness3/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is three sentences with a logical flow: purpose, return fields, parameter requirement. However, the third sentence ('commentId is required') is redundant with the schema's required field designation, wasting space that could have explained the destructive behavior.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
It lists return fields (id, objectType, etc.), which is helpful since no output schema exists. However, given the destructive annotations and mutation hints, the description is dangerously incomplete—it does not explain the side effects, success/failure states, or what actually happens to the comment resource when invoked.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema coverage, the baseline is 3. The description repeats that commentId is required, which adds no semantic value beyond the schema. It does not provide format examples, validation rules, or explain how the ID is obtained.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose3/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description states it 'Returns a single comment by its ID,' providing a clear verb and resource. However, this clarity is undermined by the destructiveHint=true and readOnlyHint=false annotations, which suggest mutation/deletion rather than simple retrieval, creating confusion about the actual purpose.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description notes that commentId is required, but this merely duplicates the schema requirements. It provides no guidance on when to use get_comment versus the sibling get_comments (plural), nor does it explain why this specific 'get' operation has destructive properties while others do not.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description explicitly states 'Read-only' which directly contradicts the annotations (readOnlyHint: false, destructiveHint: true). This is a serious safety-critical inconsistency that misrepresents the tool's behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness3/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Extremely brief at two sentences, which would normally be efficient. However, the second sentence contains erroneous information, meaning not every sentence earns its place positively. Front-loading is acceptable but content is flawed.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a single-parameter retrieval tool, the description barely suffices, but fails critically by not addressing the destructive nature indicated in annotations. No mention of error cases (e.g., item not found) or return values leaves significant gaps.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema coverage, the schema adequately documents the itemId parameter. The description adds no additional semantic information about ID format, valid sources, or examples, meeting the baseline for high-coverage schemas.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose3/5
Does the description clearly state what the tool does and how it differs from similar tools?
States the specific action (Get) and resource (single dataset item by ID), distinguishing it from sibling list_dataset_items. However, the 'Read-only' claim creates confusion given the contradictory destructive annotations, slightly undermining clarity.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Provides no guidance on when to use this tool versus alternatives like list_dataset_items, nor does it mention prerequisites such as needing a valid item ID from a dataset. The description assumes context without stating it.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Explicitly claims 'Read-only' but annotations indicate destructiveHint: true and readOnlyHint: false. This is a direct contradiction that misrepresents the tool's safety profile and potential side effects.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness3/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Two-sentence structure is appropriately brief, but dedicates one sentence to the incorrect 'Read-only' claim, wasting limited descriptive space on misleading information.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Fails to address the destructive nature implied by annotations, provides no output format details, and doesn't explain what constitutes a 'trace' in Langfuse or why fetching user traces might be destructive.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Mentions 'pagination' providing context for page/limit parameters, but with 100% schema coverage already describing all three parameters, the description adds limited semantic value beyond the structured schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose3/5
Does the description clearly state what the tool does and how it differs from similar tools?
States it retrieves traces for a specific user with pagination, but the 'Read-only' claim contradicts the destructiveHint: true annotation, creating confusion about whether this is a query or destructive operation.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance on when to use this versus siblings like fetch_traces or get_user_sessions, nor any warning about the destructive behavior indicated by annotations.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description explicitly claims 'Read-only' which directly contradicts the annotations (readOnlyHint: false, destructiveHint: true). This is a serious inconsistency that could lead to unsafe agent behavior. The description fails to disclose what gets destroyed or why openWorldHint is true.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness3/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is brief and front-loaded, but the 'Read-only' sentence is not only unhelpful but dangerously misleading given the destructive annotation. Every sentence should earn its place; the second sentence fails this criteria.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the destructiveHint annotation and lack of output schema, the description should explain what gets destroyed/modified and what the tool returns. It addresses neither, leaving significant behavioral gaps uncovered.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The mention of 'pagination' adds semantic context for the 'page' and 'limit' parameters beyond the schema's basic descriptions. With 100% schema coverage, the schema carries the primary descriptive burden, and the description provides minimal additional parameter-specific guidance.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose3/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description states the core action ('List items in a dataset') and scope ('with pagination'), which is clear. However, the 'Read-only' claim contradicts the annotations (destructiveHint: true), undermining the accuracy of the purpose description.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance provided on when to use this versus sibling tools like 'get_dataset_item' (single item retrieval) or 'list_datasets' (listing datasets themselves). No mention of prerequisites or when-not-to-use.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Critical contradiction: description states 'Read-only' but annotations specify 'readOnlyHint: false' and 'destructiveHint: true', implying data destruction. While it lists return fields ('Returns: id, traceId...'), the safety profile contradiction makes this actively misleading.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness3/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Efficiently structured with four discrete lines covering purpose, parameter hint, return values, and safety. However, two of these lines contain false information ('optional', 'Read-only'), meaning the brevity trades off with accuracy.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
With 8 required parameters and no output schema, the tool is moderately complex. The description lists return fields, which helps, but fails to explain why all filters are required (unusual for a list endpoint), pagination mechanics, or the destructive behavior indicated by annotations.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100%, establishing a baseline of 3, but the description misleadingly claims filters are 'optional' when all 8 parameters are required. It repeats the dataType enum values already present in the schema ('NUMERIC | CATEGORICAL | BOOLEAN') without adding syntax clarification or explaining the unusual 'all required' constraint.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
States specific verb+resource ('List evaluation scores') clearly. However, fails to distinguish from sibling tool 'get_score' (singular vs plural), and inaccurately describes parameters as 'optional' when the schema marks all 8 as required.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Lacks explicit guidance on when to use this vs 'get_score' or other alternatives. The phrase 'with optional filters' provides minimal implicit guidance, but contradicts the schema's required parameter constraint and gives no sense of pagination usage or filter combination behavior.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description claims 'Read-only' but annotations declare 'readOnlyHint: false' and 'destructiveHint: true'. This is a direct contradiction that misrepresents the operation's safety profile. The description fails to disclose what destructive action occurs (deletion, modification) or why 'openWorldHint' is true.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness3/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The two-sentence structure is appropriately concise and front-loaded, but the brevity is undermined by the inclusion of the erroneous 'Read-only' claim which wastes no words but conveys false information.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a destructive operation (per annotations), the description inadequately explains the consequences or side effects. With no output schema and minimal description, critical behavioral context is missing despite the simple single-parameter input structure.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema description coverage, the parameter 'scoreId' is already fully documented as 'Score ID' in the schema. The description adds no additional semantic value regarding the parameter's format or usage, warranting the baseline score for high-coverage schemas.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool 'Fetch[es] a single evaluation score by ID', specifying the verb (fetch), resource (evaluation score), and scope (single/by ID), which distinguishes it from sibling 'get_scores'. However, the accuracy is compromised by the contradictory safety claim.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance is provided on when to use this single-item fetch versus the plural 'get_scores', nor are prerequisites or alternatives mentioned. The description is too minimal to guide tool selection.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description explicitly states 'Read-only.' as the final sentence, which directly contradicts the annotations: readOnlyHint=false and destructiveHint=true. This is a serious safety inconsistency that could lead to incorrect tool selection. The description also fails to explain the openWorldHint=true annotation.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness3/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The three-sentence structure is appropriately concise with information front-loaded. However, the final 'Read-only.' sentence contains erroneous information that contradicts annotations, reducing the score.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Lacks output schema coverage (no return value description). Combined with the contradictory safety claim and lack of behavioral details (e.g., pagination behavior), the description is incomplete for safe invocation despite the input schema being well-documented.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema description coverage (page and limit both documented), the description appropriately does not redundantly describe pagination parameters. No additional semantic context (e.g., default values, max limits) is provided, warranting a baseline score.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the action (List) and resource (score config schemas) with specific details about what configs contain (NUMERIC/CATEGORICAL/BOOLEAN constraints). While it implies bulk retrieval via 'List all', it does not explicitly differentiate from sibling 'get_score_config' (singular).
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance provided on when to use this tool versus alternatives like 'get_score_config' (singular) for retrieving specific configs, or when pagination is required. No prerequisites or exclusions mentioned.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Description claims 'Read-only' which directly contradicts annotations (readOnlyHint: false, destructiveHint: true). Annotations indicate this is destructive and not read-only; description fails to disclose this dangerous behavior or explain why a list operation would be destructive.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness3/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Two sentences, appropriately brief and front-loaded. However, the second sentence contains contradictory safety information, reducing utility.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Fails to explain the destructive nature (per annotations), doesn't mention that both pagination parameters are required, and omits return format details. Incomplete for a tool with destructive behavior.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema has 100% description coverage for both parameters (page, limit). Description adds no semantic value beyond schema, meeting the baseline 3 for high-coverage schemas.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
States specific verb 'List' and resource 'evaluation datasets' with scope 'in the Langfuse project'. Clear purpose but does not explicitly differentiate from sibling get_dataset or list_dataset_items.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Provides no guidance on when to use this versus get_dataset (single retrieval) or list_dataset_items. No mention of required pagination parameters or prerequisites.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Description frames operation as safe retrieval ('Returns...'), but annotations declare destructiveHint=true. No explanation of what gets destroyed (archived? deleted? marked as consumed?) or why a 'get' operation is destructive.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Three sentences. Return field listing is justified given lack of output schema. Minor redundancy stating parameter requirement that schema already enforces.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Lists return fields adequately for missing output schema, but critically omits explanation of destructive behavior indicated by annotations. Does not clarify relationship between queue and items.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema has 100% coverage with queueId described. Description redundantly states 'queueId is required' but adds no semantic context (format, UUID vs integer, where to obtain it).
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
States specific action (Returns) and resource (annotation queue) with scope (single by ID). Distinguishes from list_annotation_queues (plural) and get_annotation_queue_item (items vs queue container).
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance on when to use this versus list_annotation_queues or create_annotation_queue. No mention of prerequisites or workflow context.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Description claims 'Read-only' but annotations explicitly declare 'readOnlyHint: false' and 'destructiveHint: true'. This is a direct contradiction that misrepresents the tool's safety profile and side effects.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Extremely concise at two sentences. However, the second sentence ('Read-only.') is factually incorrect based on annotations, meaning not every sentence earns its place constructively.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the destructive annotation contradicting the 'get' naming, the description fails to explain what side effects occur or why it is marked destructive. No output schema exists, yet the description does not characterize the return value.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema coverage, the baseline is 3. The description mentions 'by name' which aligns with the schema's 'exact match' description but adds no additional semantic context about the parameter format or constraints beyond what the schema already provides.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
States specific action (Get) and resource (Langfuse dataset) with lookup method (by name). However, it does not explicitly differentiate from sibling 'list_datasets' or 'get_dataset_item'.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Provides no guidance on when to use this specific lookup versus 'list_datasets' or how it relates to the dataset lifecycle. No prerequisites or conditions mentioned.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
CRITICAL CONTRADICTION: Description explicitly states 'Read-only' but annotations declare readOnlyHint=false and destructiveHint=true. This is a severe safety misrepresentation that could mislead agents into invoking destructive operations under the assumption they are safe reads.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is highly concise at only two sentences with no冗余. However, the brevity backfires as the second sentence ('Read-only.') contains the critical contradiction, preventing a perfect score.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
The description fails to address the surprising destructive behavior indicated by annotations, lacks output format details, and provides no error conditions. The false safety claim renders the behavioral description incomplete and potentially hazardous.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema coverage and a single parameter fully described in the schema as 'Score config ID', the baseline is appropriate. The description adds no additional semantics, examples, or format guidance beyond the schema definition.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly identifies the action ('Get') and resource ('score config schema') with specific scoping ('by ID'), distinguishing it from the plural sibling 'get_score_configs'. However, the 'Read-only' claim introduces ambiguity given the contradictory destructive annotation.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No explicit guidance on when to use this singular retrieval versus 'get_score_configs' (plural list) or how it relates to 'get_score'. The description only states functionality without comparison to alternatives.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Critical contradiction: Description explicitly states 'Read-only' but annotations declare 'destructiveHint: true' and 'readOnlyHint: false'. This misrepresents the tool's safety profile and could lead to accidental data destruction. The description also fails to explain what gets destroyed despite the destructive hint.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Two short sentences with efficient structure. However, the 'Read-only' statement earns no credit since it contradicts annotations, reducing effective information density.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
With destructive annotations present, the description should explain the mutation behavior (what gets deleted/destroyed when fetching details?). Instead, it falsely claims read-only status. No output schema guidance provided.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100% (sessionId fully documented). Description implies the single-entity nature ('one session') but adds no semantic detail beyond the schema's 'Session ID' label. Baseline 3 appropriate given complete schema coverage.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
States specific action (get full details) and scope (one session including traces). Clear verb-resource combo. However, fails to distinguish from sibling tools like 'fetch_sessions' or 'get_user_sessions' which likely overlap in functionality.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Provides no guidance on when to select this tool versus alternatives such as 'fetch_sessions' or 'get_user_sessions'. No prerequisites or conditions for use are mentioned.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description explicitly states 'Read-only' which directly contradicts the annotations (readOnlyHint: false, destructiveHint: true). This misrepresents the tool's safety profile and potential side effects, creating a serious risk of misuse.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is extremely concise at only two short sentences. However, the second sentence ('Read-only.') wastes its place by stating false information, preventing a perfect score.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
With destructiveHint:true and no output schema, the description fails to explain what state changes occur (what gets destroyed) or what data structure returns. The contradiction regarding read-only behavior leaves the agent without accurate behavioral context.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100%, so the schema fully documents all three parameters (userId, page, limit). The description mentions 'pagination' and 'specific user', providing minimal semantic mapping but not adding syntax details or validation rules beyond the schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly identifies the resource (sessions), the scope (for a specific user), and the mechanism (pagination). However, the claim of being 'Read-only' creates confusion given the contradictory annotations, slightly diminishing clarity.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance provided on when to use this versus sibling tools like 'fetch_sessions' or 'get_session_details', nor when to stop paginating. The only usage hint is 'pagination', which merely describes the interface pattern.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
CRITICAL: Description claims 'Read-only.' but annotations specify 'readOnlyHint: false' and 'destructiveHint: true'. This is a direct contradiction that could mislead an agent about safety. With destructiveHint true, the description completely misses critical behavioral implications.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Two short sentences, front-loaded with the action. Every word earns its place, though the final sentence contains false information regarding safety.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the destructiveHint:true annotation (which suggests dangerous side effects), the description dangerously under-specifies behavior. No output schema exists, yet the description fails to compensate or explain what 'destruction' might occur during a listing operation.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100% with clear descriptions for 'page' and 'limit'. The description mentions 'pagination' which contextualizes these parameters, but does not add syntax, format constraints, or valid ranges beyond the schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
States specific verb (List), resource (prompts in Langfuse project), and scope (all prompts with pagination). However, it does not explicitly distinguish from sibling tool 'get_prompt' which presumably fetches a single prompt.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Provides no guidance on when to use this tool versus alternatives like 'get_prompt' or when pagination is necessary. No mention of required parameters or typical pagination patterns.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare destructiveHint=true and idempotentHint=false, but description doesn't explain what gets destroyed/overwritten or warn about non-idempotent behavior. The 'provide only fields you want to change' claim suggests PATCH semantics while schema enforces PUT semantics (all required), creating confusion about actual behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Brief and front-loaded with purpose. However, extreme brevity given the destructive nature and schema complexity leaves critical gaps; the partial-update claim appears in sentence 3 without qualification.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a destructive mutation tool (destructiveHint=true) with 7 parameters, the description is dangerously incomplete. No output schema exists, yet description fails to clarify the destructive scope, doesn't reconcile the partial-update claim with required schema constraints, and omits warnings about data loss.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Despite 100% schema coverage (baseline 3), the description introduces misleading semantics by claiming partial updates are possible when the schema marks all 7 parameters required. The categoriesJson format note merely repeats schema content rather than adding value.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
Clear verb 'Updates' and resource 'score config' with specific target (existing). Distinguishes from sibling create_score_config by targeting existing items, though could clarify what a score config represents.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
States 'configId is required' and suggests partial updates ('provide only the fields you want to change'), but fails to explain when to use update vs create_score_config, doesn't address destructiveHint=true implications, and the partial update instruction contradicts the schema's all-fields-required constraint.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description contradicts the annotations. Annotations declare 'readOnlyHint: false' and 'destructiveHint: true', implying a mutation or destructive operation, while the description frames this as a safe retrieval ('Returns items'). This inconsistency could cause dangerous misuse by the agent.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is appropriately front-loaded with the primary purpose, followed by filter details and return structure documentation (valuable given no output schema exists). Minor redundancy exists in stating 'queueId is required' (already in schema required array).
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness3/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Without an output schema, documenting the return item fields (id, queueId, traceId, etc.) is necessary and helpful. However, the description omits critical behavioral context regarding the contentious 'destructive' and 'openWorld' hints, leaving the agent unprepared for side effects.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema description coverage, the baseline is 3. The description repeats the enum values (PENDING | COMPLETED) and 'omit' behavior already documented in the status parameter description, adding no new semantic depth. It redundantly notes 'queueId is required' which the schema already enforces.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the specific action ('Returns') and resource ('items in a specific annotation queue'), distinguishing it from sibling 'get_annotation_queue' by pluralization and content detail. However, it fails to hint at the destructive/non-read-only nature implied by annotations, slightly obscuring the true purpose.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides no guidance on when to use this tool versus alternatives like 'get_annotation_queue_item' (singular) or 'list_annotation_queues'. It explains the status filter behavior but offers no strategic usage context or prerequisites for the agent.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior3/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description adds valuable behavioral context beyond annotations: it discloses the side effect of creating/updating the parent dataset run, and notes the JSON validation requirement for metadataJson. Annotations indicate destructiveHint=true, which aligns with the 'Creates' action. However, the description contradicts the input schema regarding parameter optionality, which could mislead the agent about invocation requirements.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is appropriately concise with three sentences that are front-loaded (purpose first, then constraints). Each sentence earns its place without redundancy. Minor structural issue: the second sentence jams two field requirements together with 'and' while the third covers three different constraints.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool has 8 parameters (all marked required in schema), destructive annotations, and complex side effects (upserting parent run), the description covers the main behavioral intent but is compromised by incorrect parameter requirement documentation. With no output schema, the description appropriately focuses on input requirements, but the contradictions make it incomplete.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters1/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The description actively contradicts the input schema for 6 of 8 parameters: it states traceId is 'strongly recommended' and observationId is 'optional,' while the schema marks them as required. Similarly, it implies metadataJson is optional ('when provided'), but the schema requires it. While it adds the JSON validation constraint, the misinformation about requirement status is critical.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool 'Creates a dataset run item' (specific verb + resource) and adds the side effect that it 'creates or updates the dataset run if needed.' While it distinguishes from sibling tools like create_dataset via the resource name, it does not explicitly clarify when to use this versus create_dataset_item.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines3/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides guidance on field importance (runName/datasetItemId 'required', traceId 'strongly recommended', observationId 'optional'), which helps with invocation. However, it lacks explicit guidance on when to use this tool versus siblings like create_dataset_item or add_item_to_dataset, and mentions no prerequisites.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
While annotations indicate destructiveHint=true and openWorldHint=true, the description adds domain context (USD pricing, units). However, it introduces significant misleading information by claiming prices can be omitted and referencing a non-existent 'startDate' parameter not present in the schema.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness3/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Efficiently structured with targeted sentences, but includes wasted space describing the non-existent startDate parameter and incorrect requirement constraints.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a destructive mutation tool with 6 parameters, the description fails to accurately document the API contract. The incorrect requirement specifications and missing parameter mean the agent cannot trust the description for invocation guidance.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Despite 100% schema coverage (baseline 3), the description incorrectly states only 3 parameters are required when the schema marks all 6 as required, and references a phantom 'startDate' parameter. It does add value by enumerating unit values and providing price calculation examples.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
Description provides specific verb (Creates), resource (custom model definition), and clear domain context (cost tracking and token pricing) that distinguishes it from generic 'create' operations.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Provides guidance on omitting prices when cost tracking isn't needed, but this contradicts the schema where price fields are required. No comparison to sibling tools (e.g., get_model vs create_model) or when to use each.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations indicate destructiveHint=true and readOnlyHint=false, suggesting the operation modifies state (possibly consuming/removing the item from queue), but description only states 'Returns...' implying a safe read. Fails to explain what gets destroyed or the implications of openWorldHint=true.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Generally concise with three clear sentences. The return value documentation is necessary given no output schema exists. Minor redundancy stating parameters are required when schema already enforces this.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness3/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Documents return fields (id, queueId, traceId, etc.) which is valuable without an output schema. However, incomplete regarding destructive behavior implied by annotations and lacks guidance on error cases or side effects.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100% with clear descriptions. The description adds 'by queue ID and item ID' which maps parameters to the retrieval pattern, but otherwise repeats the required status already specified in schema's required array.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
Clearly states the tool returns a specific item by queue ID and item ID, distinguishing it from sibling 'list_annotation_queue_items' which returns multiple items. Specific verb and resource identified.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance provided on when to use this specific tool versus list_annotation_queue_items or other queue operations. Only states parameter requirements which are already evident in the schema.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
CRITICAL CONTRADICTION: The description frames this as a safe retrieval ('Returns a single...') but annotations indicate destructiveHint=true and readOnlyHint=false, implying data mutation or deletion. The description completely fails to explain why a 'get' operation is destructive, what gets destroyed, or any side effects.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Efficient 4-sentence structure that front-loads the action, explains run item semantics, and documents return fields (necessary given no output schema). Only minor redundancy in stating required parameters.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness4/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Adequately compensates for missing output schema by enumerating return fields and nested array structure (datasetRunItems). Would benefit from explaining the destructive behavior implied by annotations, but covers the data structure well.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema coverage, the baseline is 3. The description redundantly states parameters are 'required' (already in schema's required array) and doesn't add validation rules, format examples, or semantic context beyond the schema's 'exact match' specification.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
Clearly states it retrieves a single dataset run and explains what run items are (links between dataset items and traces). However, the framing as a simple 'Returns' operation slightly undersells the complexity suggested by the destructive annotation.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Lacks explicit guidance on when to use this versus the sibling 'list_dataset_runs' tool. While 'single' implies random-access retrieval, it doesn't clarify selection criteria or when listing is preferable.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description claims a simple read operation ('Returns'), but annotations indicate destructiveHint=true and readOnlyHint=false, suggesting side effects or mutation. The description completely fails to explain what gets destroyed, modified, or what the openWorldHint implies regarding external resource access.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness3/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The first sentence is efficient. However, listing all 11 return fields in prose is bulky (necessary given no output schema exists, but poorly structured). The final sentence 'modelId is required' is redundant with the schema.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness3/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
The description compensates for the missing output schema by enumerating return fields. However, given the destructive annotation and complex sibling ecosystem, it lacks explanation of behavioral implications and side effects that the agent should know before invoking.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema coverage, the schema adequately documents the modelId parameter. The description adds no semantic value beyond repeating 'modelId is required' which is already evident in the schema's required array.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool 'Returns a single model definition by its ID', specifying the verb (Returns), resource (model definition), and scope (single by ID). This effectively distinguishes it from sibling tools like list_models (which returns multiple) and create_model/delete_model.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance provided on when to use this tool versus alternatives like list_models (for browsing) or fetch_traces (which uses different terminology). No mention of prerequisites or typical use cases.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Description states 'Returns a paginated list...' implying a safe read operation, but annotations declare 'destructiveHint: true' and 'readOnlyHint: false', indicating a destructive write. This is a direct contradiction. Description fails to explain any destructive side effects if they exist.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Front-loaded with the action, efficiently structured into purpose, return fields (compensating for missing output schema), and constraints. The return value list is useful given no output schema exists.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness4/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Adequately compensates for the missing output schema by enumerating returned fields (id, name, metadata, etc.). Given simple scalar parameters and the presence of annotations (albeit contradictory), the description provides sufficient context for invocation.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100% with clear descriptions for each parameter. The tool description groups pagination parameters and notes their defaults, matching the schema. With full schema coverage, this meets the baseline, though it adds no additional semantic context beyond what's in the schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
States specific action (Returns a paginated list) and resource (runs for a specific dataset), including domain context ('Each run represents one experiment'). Distinguishes from sibling 'get_dataset_run' by emphasizing the paginated list aspect.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Mentions parameter constraints ('datasetName is required') and pagination defaults, but provides no guidance on when to use this versus 'get_dataset_run' or 'list_dataset_run_items', nor any prerequisites or error conditions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior3/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Clarifies upsert semantics beyond what annotations provide (explaining the update-when-exists logic). However, it fails to reconcile the idempotentHint=false annotation with upsert expectations, and doesn't explain the destructive impact of updates despite destructiveHint=true.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness3/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Four sentences with some redundancy (explicitly stating parameters are required when the schema already enforces this). The structure progresses logically from action to conditional behavior to requirements, though the requirement sentence is redundant.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness3/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Covers basic upsert mechanics but omits security context for secretKey handling (relevant given destructiveHint=true), doesn't explain connection usage within the system, and ignores the output implications (no output schema exists).
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema coverage, baseline is 3, but the description incorrectly states only provider and secretKey are required, omitting the adapter parameter which is also required per the schema. It also fails to explain what the adapter parameter does beyond the schema's minimal description.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
Clearly states the tool creates or updates an LLM provider connection and explains the upsert keying mechanism (by provider name). However, the title merely repeats the function name in snake_case rather than providing human-readable context.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Explains the conditional behavior (creates new if absent, updates if exists) but provides no guidance on when to use this versus list_llm_connections or other sibling tools, nor preconditions like required configuration states.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Description states 'Returns...' implying a safe read operation, but annotations declare destructiveHint=true and readOnlyHint=false. This is a direct contradiction—the description must disclose what gets destroyed or modified, or the annotation is wrong. Also fails to explain openWorldHint behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Well-structured with 4 efficient sentences: purpose first, filtering logic second, use case third, parameter guidance fourth. Front-loaded and no filler. Deduction only because it buries the critical 'optional' claim that contradicts the schema.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Lacks return value description (no output schema exists to compensate). The contradictions with both schema (required vs optional) and annotations (safe vs destructive) create significant gaps. Should clarify the actual destructive behavior if the annotation is correct, or clarify why parameters are required.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema coverage, baseline is 3. The description provides helpful semantic context ('typically a source file name such as OrderService.java') and explains time range semantics, but it actively misleads by claiming time parameters are optional when the schema marks them as required, creating integration risk.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
Excellent specificity: 'Returns ERROR-level traces whose metadata contains the given file name as a substring' clearly states the verb (returns), resource (traces), filter criteria (ERROR-level, file name substring), and distinguishes from generic trace search siblings.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines3/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Provides clear use case ('isolate errors originating from a specific source file') and mentions time range flexibility. However, it lacks explicit comparison to sibling tools (e.g., when to use find_exceptions vs this tool) and incorrectly states time parameters are optional when they are required in the schema.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
**Annotation Contradiction**: Description explicitly states 'Read-only' but annotations declare 'readOnlyHint: false' and 'destructiveHint: true'. This is a critical safety inconsistency. Additionally, it does not explain why a 'get' operation is marked destructive, nor does it address pagination behavior or 'openWorldHint' implications.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Extremely efficient four-line structure with zero waste: purpose statement, parameter constraints, return value specification, and safety hint. Each sentence delivers distinct information in minimal words.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness3/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Adequately documents return fields to compensate for missing output schema, but the behavioral contradiction and lack of sibling differentiation create critical gaps. For a simple list operation with 100% schema coverage, this would suffice if not for the safety inconsistency.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters4/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100%, establishing baseline 3. Description adds explicit return field documentation (id, content, authorUserId, etc.) which compensates for missing output schema, and reinforces objectType enum constraints beyond the schema's basic description.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
States 'List comments' with clear filtering criteria (objectType, objectId) and enumerates valid objectType values (TRACE | OBSERVATION). However, it fails to distinguish from sibling 'get_comment' (singular) which likely retrieves a single comment by ID.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Provides no explicit guidance on when to use this tool versus sibling 'get_comment' or 'create_comment'. The filtering constraints are implied by parameter documentation but lack contextual prerequisites (e.g., needing a valid trace/observation ID first).
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Description presents the tool as a simple read operation ('Returns a paginated list'), but annotations indicate destructiveHint=true and readOnlyHint=false, implying state mutation. The description fails to disclose this destructive behavior, the non-idempotent nature, or openWorld implications, contradicting the safety profile implied by the word 'Returns'.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Well-structured with purpose first, followed by domain explanation, return fields (compensating for missing output schema), and requirements. Minor redundancy in stating required parameters that are already marked required in schema.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness3/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Compensates well for missing output schema by explicitly listing return fields and explains the conceptual model. However, incomplete regarding behavioral safety given the destructive annotation contradiction, and lacks usage context relative to sibling dataset tools.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema has 100% description coverage. Description states 'Both datasetId and runName are required', which duplicates the schema's required array. No additional semantic context added for page/limit beyond what the schema provides, which warrants the baseline score for high-coverage schemas.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
Specific verb 'Returns' and resource 'dataset run items'. Distinguishes from siblings like list_dataset_runs and list_dataset_items by explaining the domain concept that 'run items link a dataset item to a trace', clarifying this is about evaluation linkage objects, not just datasets or runs.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No explicit guidance on when to use this versus siblings like list_dataset_runs, get_dataset_run, or create_dataset_run_item. While it explains what run items are, it doesn't state when to list them versus other dataset operations.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description claims this 'Returns' data (a read operation), but the annotations declare 'destructiveHint: true' and 'readOnlyHint: false', implying data destruction. This is a direct contradiction—fetching a paginated list should not be destructive. The description also fails to explain the 'openWorldHint: true' (external calls) behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is well-structured with clear sections: purpose definition, trace explanation, response fields, filter behavior, and pagination mechanics. Sentences are purposeful and information-dense. The field list is slightly verbose but necessary given the lack of output schema.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness4/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the lack of output schema, the description comprehensively lists return fields (id, name, userId, sessionId, etc.) and explains the filter/pagination behavior in detail. It adequately covers the 8-parameter complexity despite the schema incorrectly marking all fields as required.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters4/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Despite 100% schema coverage, the description adds crucial semantic context: it clarifies that 'All filter parameters are optional' (correcting the schema's erroneous 'required' array), provides the default values for pagination (page=1, limit=20), and explains the paging strategy incrementing page while keeping limit fixed.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states it 'Returns a paginated list of Langfuse traces' with a specific verb and resource. It adds valuable context by defining what a trace represents ('one end-to-end LLM pipeline execution') and enumerating response fields. However, it misses explicit differentiation from the singular 'fetch_trace' sibling.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines3/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides clear guidance on filter usage ('Omit any filter you do not need') and pagination strategy ('To page through results, increment page while keeping limit fixed'). However, it lacks explicit comparison to siblings like 'fetch_trace' or 'get_user_traces' to help the agent choose between bulk retrieval and specific lookups.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior2/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations indicate destructiveHint=true and readOnlyHint=false, but the description only describes read behavior ('Returns', 'Filtering'), failing to disclose what gets destroyed or modified. It does add valuable behavioral context about server-side filtering guarantees ('Filtering is performed on the server...never a mix of levels'), but the omission of destructive behavior given the annotation is a critical gap.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is well-structured with four sentences front-loaded by purpose, followed by behavioral guarantees, use cases, and parameter guidance. Every sentence adds distinct value. However, the sentence about optional parameters propagates misinformation given the schema's required array.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the destructive annotation and the read-oriented description, the definition lacks necessary completeness. The parameter optionality contradiction and unexplained destructive behavior leave critical gaps. Without an output schema, the description adequately explains the return concept (error traces) but fails to resolve safety concerns raised by the annotations.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
While the input schema has 100% description coverage, the description contradicts the schema regarding parameter optionality: it states 'Both time range parameters are optional. Omit them...', but the schema marks fromTimestamp and toTimestamp as required. This contradiction creates ambiguity about whether the tool can be called without time bounds.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description opens with a precise, specific verb and resource ('Returns only traces whose level field equals ERROR') that clearly distinguishes this from siblings like fetch_traces (general traces) and get_error_count (likely numeric counts). It identifies the exact filter criteria (level=ERROR) and scope.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines3/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides contextual usage ('Useful for surfacing pipeline failures and debugging production errors') and references sibling fetch_traces for pagination behavior, helping users understand the relationship. However, it lacks explicit guidance on when NOT to use this vs. alternatives like get_exception_details or find_exceptions_in_file, and doesn't address the destructive annotation implication.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description characterizes this as a read operation ('Returns'), which directly contradicts the annotations declaring `destructiveHint: true` and `readOnlyHint: false`. This inconsistency makes it impossible to trust the described safety profile.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The four sentences are well-structured and front-loaded: purpose (list), return structure (fields), business context (human-in-the-loop), and pagination mechanics. Each earns its place, though the field enumeration could be more concise.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness4/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given no output schema exists, the description adequately compensates by enumerating returned fields (id, name, description, etc.) and explaining the business purpose (human-in-the-loop workflows). It covers the essential behavioral contract for a paginated list operation.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters4/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Despite 100% schema coverage, the description adds crucial semantic context: clarifying that pagination is '1-based' (not 0-based) and restating default values (page=1, limit=20) that might otherwise be buried in schema defaults.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool 'Returns a paginated list of annotation queues' with specific resource and scope (Langfuse project). It distinguishes from sibling `get_annotation_queue` (singular) by emphasizing pagination and listing multiple items, though it doesn't explicitly name the alternative.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines3/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides implied usage through pagination guidance ('page is 1-based', default values), but lacks explicit guidance on when to use this listing tool versus `get_annotation_queue` for single-record retrieval or filtering capabilities.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior3/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already indicate destructiveHint=true and readOnlyHint=false. The description adds value by specifying the valid status values (PENDING | COMPLETED) and implying a state machine, but does not elaborate on side effects, failure modes, or what 'destructive' entails in this context.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is appropriately concise with three short, front-loaded sentences. Each sentence serves a distinct purpose (action definition, value constraints, required fields), though the last two largely mirror schema information.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness4/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the presence of comprehensive annotations and 100% schema coverage, the description provides sufficient context for the tool's limited complexity. It covers the domain-specific logic (status values) that structured fields cannot express, though it could note that queueId/itemId typically come from list/get operations.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema description coverage, the baseline is 3. The description repeats the valid status values and required fields that are already documented in the parameter schemas, adding no new semantic meaning beyond what the schema provides.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the specific action (Updates) and resource (annotation queue item status). However, it does not explicitly differentiate from siblings like 'create_annotation_queue_item' or 'delete_annotation_queue_item' within the text itself, relying on the tool name for distinction.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides constraints (valid status values, required parameters) but lacks explicit guidance on when to use this tool versus alternatives like create_annotation_queue_item or delete_annotation_queue_item. It tells how to use it, not when to choose it.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior3/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Adds validation constraints not in annotations ('must be valid JSON') and discloses return value ('Returns the created dataset definition'). Annotations already establish destructive/mutable nature; description doesn't elaborate on openWorld implications or error conditions like name conflicts.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Five short sentences with minimal waste. Front-loaded with primary action. Slight redundancy with schema on required/optional status, but efficiently packs JSON validation requirements and return value info.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness3/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Adequate for a 5-parameter creation tool with strong schema coverage and annotations. Mentions return value (compensating for missing output schema). Missing: error handling (duplicate names), side effect details, or relationship to dataset item operations.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters4/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema coverage, baseline is 3. Description adds crucial behavioral constraint that three JSON parameters require valid JSON syntax ('must be valid JSON when provided'), which schema field descriptions don't specify. Redundant on required/optional status.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose4/5
Does the description clearly state what the tool does and how it differs from similar tools?
Clear verb ('Creates') and resource ('dataset') with scope ('in Langfuse'). Effectively distinguishes from siblings like create_dataset_item (creates items within datasets) and list_datasets (read operation).
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Provides parameter-level guidance (required vs optional) but lacks tool-level usage guidance: no mention of when to create new datasets versus using existing ones (via get_dataset/list_datasets), or prerequisite relationships to create_dataset_item.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description explicitly states 'Read-only,' which directly contradicts the annotations that specify 'destructiveHint': true and 'readOnlyHint': false. This is a serious inconsistency that could lead an agent to incorrectly assume this is a safe read operation when it may have destructive side effects.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is appropriately compact with four focused sentences covering purpose, parameter semantics, return values, and safety. The structure is logical, though the final 'Read-only' sentence contains erroneous information.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
The description compensates for the missing output schema by enumerating return fields (name, version, type, etc.). However, it is incomplete due to contradictions: claiming optional parameters ('Optionally pin') when the schema marks all three as required, and claiming read-only behavior when annotations indicate destructiveness.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters4/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
While the schema has 100% description coverage, the description adds valuable semantic context by introducing the 'pinning' metaphor for version and label parameters, helping agents understand these are for selecting specific variants. It reinforces the examples (production, staging) provided in the schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool's purpose with specific verb ('Fetch') and resource ('prompt'), and specifies the identification method ('by name'). It effectively distinguishes from siblings like create_prompt, delete_prompt, and list_prompts.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines3/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Provides implicit usage guidance by explaining the 'pinning' concept for version/label (e.g., production vs staging), which helps users understand when to use those parameters. However, it lacks explicit guidance on when to use this tool versus list_prompts for discovery or create_prompt for generation.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description frames the operation as a safe read ('Returns a paginated list'), but the annotations declare destructiveHint: true and readOnlyHint: false. This direct contradiction regarding whether the tool modifies/deletes data versus merely querying is a critical transparency failure that could mislead agents about operation safety.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Four efficiently structured sentences progress logically from operation definition to return fields to usage context to pagination mechanics. Every sentence earns its place, though the field enumeration (id, provider, etc.) is slightly dense and could benefit from formatting separation.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness4/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the lack of an output schema, the description commendably details the structure of returned connection objects (listing fields like displaySecretKey and baseURL). It also establishes the domain context (Langfuse project, evaluations). Only minor gap is explicit differentiation from the upsert sibling.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema description coverage, the schema already fully documents both parameters (page and limit). The description reinforces that page is 1-based and limit controls page size, but adds no significant semantic detail beyond what the schema provides, meriting the baseline score for high-coverage schemas.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool 'Returns a paginated list of LLM provider connections configured in the Langfuse project', specifying the exact resource, the action (returns/list), and the scope. This effectively distinguishes it from the mutation-focused sibling 'upsert_llm_connection'.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines3/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Provides domain context stating connections are used 'for evaluations and playground', implying when the tool is relevant. However, it lacks explicit guidance on when to use this list operation versus creating/updating connections via the sibling tool, or when pagination is necessary.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior3/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare destructiveHint:true and idempotentHint:false. The description adds domain context ('human review') but does not explain these behavioral traits or what happens on duplicate calls.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Four short sentences with logical structure: purpose first, then parameter constraints. Efficient though slightly repetitive with schema content.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness3/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Adequate for a 4-parameter creation tool with annotations present. Omits return value description (no output schema exists) and error conditions, but covers essential inputs.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema description coverage, the baseline is 3. The description repeats enum values (SESSION/TRACE/OBSERVATION, PENDING/COMPLETED) already present in schema descriptions without adding semantic value or parameter relationships.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool 'Adds an item to an annotation queue' with the specific context 'for human review', distinguishing it from sibling create_annotation_queue which creates the queue structure itself.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
While it mentions the domain context ('for human review'), there is no guidance on when to use this versus alternatives like update_annotation_queue_item, or workflow prerequisites.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description uses 'Returns' implying a safe read operation, which contradicts the annotations declaring destructiveHint=true and readOnlyHint=false. It also fails to explain the openWorldHint=true (external system calls) or disclose why a 'get' operation would be destructive. This is a serious inconsistency.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Two well-structured sentences. The first establishes core functionality; the second provides scope-dependent usage context. Every sentence earns its place with zero redundancy.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
While the description adequately explains the variance in return cardinality (one vs many projects), it fails to address the destructive nature indicated by annotations or resolve the contradiction with the 'Returns' verb. For a tool with destructive implications, this omission is significant.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters4/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The input schema has zero parameters (empty object) with 100% description coverage. For tools with no parameters, the baseline is appropriately met without additional parameter documentation needed.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
Description clearly states the tool 'Returns the project or projects visible to the currently configured API key' — specific verb, resource, and scope. It further distinguishes behavior for project-scoped keys (returns one) vs broader credentials (returns many), providing clear differentiation.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines3/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Provides contextual usage guidance ('With broader credentials, use this to confirm which project metadata is available'), implying when the tool is valuable. However, it lacks explicit comparison to sibling tools (e.g., when to use this vs other list/get operations) and does not state prerequisites or exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
CRITICAL CONTRADICTION: Description states 'Returns a paginated list' implying a safe read operation, but annotations declare 'destructiveHint: true' and 'readOnlyHint: false'. This is a severe inconsistency that would mislead an agent about the tool's safety profile and side effects.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Three logically sequenced sentences: (1) operation purpose, (2) returned fields (compensating for missing output schema), (3) pagination mechanics. No redundant words; field enumeration is necessary given no output schema. Front-loaded with the essential action and scope.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness4/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Strongly compensates for missing output schema by enumerating all 10 returned fields. Covers pagination defaults and project scope. Only gap is missing contrast with 'get_model' for single-record retrieval, though this is implied by 'paginated list'.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema has 100% description coverage ('Page number, 1-based' and 'Results per page'), establishing baseline 3. Description adds marginal semantic grouping under 'Pagination' header and reinforces '1-based' nature, but largely repeats schema information without adding syntax details or validation rules beyond what's structured.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
Excellent specificity: verb 'Returns' + resource 'models' + scope 'in the Langfuse project' + differentiation between 'Langfuse-managed' and 'custom' models. Clearly distinguishes from sibling 'get_model' by emphasizing 'paginated list' vs singular retrieval.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines3/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Provides implied usage context through pagination documentation (page is 1-based, default limits), helping agents understand how to navigate results. However, lacks explicit guidance on when to use this versus 'get_model' or how to choose between listing and fetching specific resources.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior4/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Adds valuable return value information ('Returns the created queue with its assigned ID') not present in annotations or output schema. Annotations already cover safety profile (destructiveHint=true, readOnlyHint=false), so description appropriately focuses on workflow context and return structure without contradiction.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Three tightly focused sentences covering purpose, return value, and parameters. Structure is front-loaded, though the third sentence contains the parameter requirement inaccuracy.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness3/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Adequate for a creation tool with good annotations and full schema coverage. Describes return values sufficiently given the lack of output schema, but the parameter requirement error leaves a critical gap.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters2/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Attempts to clarify required vs optional parameters ('name is required... are optional'), but this contradicts the input schema which marks all three parameters as required. With 100% schema coverage, baseline is 3, but the misinformation reduces the score.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
Clear specific verb (Creates), resource (annotation queue), and scope (for human review workflows). Distinguishes from sibling create_annotation_queue_item by specifying 'queue' vs 'item'.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No explicit guidance on when to use versus alternatives (e.g., when to create a queue vs. adding items to existing queues). Only states what the tool does, not when to invoke it or prerequisites.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Description frames the operation as a safe read ('Returns the full detail') but annotations indicate destructiveHint=true and readOnlyHint=false. This is a serious contradiction—the description implies non-destructive retrieval while annotations declare destructive behavior, and the description fails to disclose what gets destroyed.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Three sentences with zero waste: purpose declaration first, response payload details second, usage context third. Every sentence earns its place and the description is appropriately front-loaded.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness3/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
While the description adequately explains what the response includes (observations, payloads, metadata) compensating for the lack of output schema, it is incomplete regarding behavioral traits—specifically, it omits the destructive behavior indicated by the destructiveHint annotation, creating a critical safety documentation gap.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100%, so the schema fully documents the traceId parameter (UUID, required). The description mentions 'The traceId is required' and 'identified by its ID' but adds minimal semantic detail beyond what the schema already provides, meeting the baseline for high-coverage schemas.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
Description clearly states the tool 'Returns the full detail of a single Langfuse trace' using specific verb (Returns) and resource (trace). The 'single' qualifier effectively distinguishes this from the plural sibling fetch_traces.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines4/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Provides explicit workflow guidance: 'Use this after fetch_traces to drill into a specific trace.' This clearly sequences the tool in relation to its sibling (fetch_traces), though it lacks explicit 'when not to use' exclusions or alternative recommendations.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Description states 'Mirrors: GET /api/public/metrics' and frames as a read query, but annotations declare destructiveHint=true and readOnlyHint=false. This is a direct contradiction regarding the safety profile of the operation.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness3/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Extremely verbose with heavy ASCII art separators consuming tokens. While the detailed examples and field documentation are necessary for the complex JSON DSL, the formatting is inefficient for LLM context windows and could be compressed.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness2/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Despite rich input documentation, there is zero description of return values or response structure, and no output schema is present. For a metrics aggregation tool, this omission leaves the agent blind to what data structure will be returned.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters5/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Despite 100% schema coverage for the single 'query' parameter, the description adds massive value by detailing the JSON structure's internal semantics: valid enums for views, measures by view type, aggregation functions, dimension fields, and filter operators with explicit constraints.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description opens with specific verb 'Query' and precise resource 'Langfuse cost, token, latency, and usage analytics via the Metrics API', clearly distinguishing this aggregation-focused tool from sibling fetch/get tools that retrieve raw records.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines4/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Extensive internal guidance provided: explicit view selection guidance ('USE for model breakdowns'), measure/aggregation mapping ('sum → cost/token totals'), and critical constraints ('⚠ NEVER use inputTokens...'). Lacks explicit comparison to siblings like fetch_traces.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
ANNOTATION CONTRADICTION: Description explicitly states 'Read-only' but annotations declare readOnlyHint: false and destructiveHint: true. This is a critical safety mismatch. Additionally fails to explain openWorldHint: true implications (external dependencies) or output format.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness3/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Three-sentence structure is appropriately front-loaded (what, when, safety), but the 'Read-only' sentence earns no place since it contradicts annotations and misleads the agent about safety profile.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness3/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Describes the return value conceptually (schema, types, enums) which compensates somewhat for missing output schema. However, the annotation contradiction creates a critical gap in behavioral understanding, and no pagination or format details are provided.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters4/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Input schema has zero parameters, establishing baseline of 4. No parameters require semantic explanation beyond the schema definition.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
Excellent specificity: states the verb (Returns), resource (Langfuse data model schema), and detailed scope (all entity types, fields, and valid enum values). Clearly distinguishes from sibling data-fetching tools like fetch_traces or get_dataset by focusing on metadata/schema rather than instance data.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines4/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Strong explicit guidance: 'Call this first before running any query to understand the available data structures' establishes prerequisite usage and explains the 'why.' Would be perfect (5) if it explicitly contrasted with specific alternatives like fetch_traces.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior3/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Adds valuable safety context beyond annotations by stating 'This action is irreversible,' reinforcing the destructiveHint. However, it omits implications of idempotentHint=false (what happens on re-invocation) and openWorldHint=true, and doesn't mention cascade effects or error cases (e.g., trace not found).
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Extremely concise with three short sentences. Front-loaded with the primary action, zero redundancy, and every sentence earns its place—the irreversibility warning is critical for a destructive tool.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness4/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Adequate for a simple single-parameter deletion tool. Captures the destructive nature and required parameter. Could be improved by noting the response behavior (e.g., void/empty on success) or 'not found' error conditions, but acceptable given the low complexity and presence of annotations.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema coverage, the schema already fully documents the traceId parameter. The description merely repeats 'traceId is required,' adding no semantic depth, syntax examples, or format guidance beyond the structured schema definition.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
Specific verb (Deletes), resource (trace), and scope (single by ID) clearly stated. The 'single' qualifier effectively distinguishes this from the sibling 'delete_traces' (batch deletion) without needing explicit naming.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines2/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance provided on when to use this single-trace delete versus the sibling 'delete_traces' for batch operations, nor any prerequisites or conditions. Only states parameter constraints ('traceId is required'), not usage context.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior3/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description adds 'This action is irreversible', elaborating on the destructiveHint=true annotation. However, it fails to explain behavioral implications of openWorldHint=true (external side effects) or idempotentHint=false (likely errors on second deletion), which are critical for a delete operation.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Two sentences with zero waste. The first sentence front-loads the action and target; the second provides the critical safety warning. No fluff or redundancy.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness4/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a single-parameter deletion tool with destructive hints and no output schema, the description covers the essential safety warning. Minor gaps remain regarding error semantics (what happens if ID not found?) implied by idempotentHint=false.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100% with the itemId parameter fully described. The description references 'its ID' corroborating the schema, but adds no additional semantic context about ID format, validation rules, or sourcing beyond the schema definition.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description states the specific verb 'Deletes', resource 'dataset item', and scope 'by its ID', clearly distinguishing it from sibling tools like delete_dataset, delete_annotation_queue_item, or delete_trace.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines3/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description includes the warning 'This action is irreversible', which hints at consequences but lacks explicit guidance on when to select this tool versus alternatives (e.g., delete_dataset for entire datasets) or prerequisites (e.g., obtain ID via list_dataset_items).
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior1/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description presents this as a read-only operation ('Returns', 'inspect'), but annotations declare readOnlyHint: false and destructiveHint: true. This is a serious contradiction—the description fails to disclose what gets destroyed or why a 'get' operation is flagged as destructive.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Well-structured with clear information hierarchy: purpose statement first, sibling differentiation second, usage context third, parameter requirement last. No wasted words or redundant phrases.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness4/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Compensates well for missing output schema by detailing response contents ('includes all nested observations, input/output, metadata, and timing'). workflow context with find_exceptions is helpful. Minor gap: does not address the destructiveHint implication or potential side effects.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100%, so the schema fully documents the traceId parameter including its format and requirement. The description adds 'The traceId is required' but this merely duplicates the schema's 'required' constraint without adding semantic context (e.g., where to obtain the ID). Baseline 3 appropriate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool 'Returns the full detail of a single ERROR-level trace' and explicitly distinguishes it from the sibling 'fetch_trace' by noting it is 'semantically scoped to error traces.' Specific verb+resource+differentiation present.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines5/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Provides explicit workflow guidance: 'Use this after find_exceptions to inspect a specific failure in depth.' Also notes the equivalent alternative ('Equivalent to fetch_trace') while clarifying when to prefer this tool (error-specific cases).
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior4/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description aligns well with annotations (readOnlyHint: false matches 'Creates') and adds valuable information about the return value ('Returns the created comment with its assigned ID') which is not present in the structured annotations. It does not explicitly address the destructiveHint: true implication or openWorldHint: true, but 'Creates' sufficiently implies state mutation.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is three sentences long with the main action front-loaded in the first sentence. The second sentence combines enum specification with requirement statements efficiently. There is minimal redundancy or wasted text, though the enum repetition is slightly redundant with the schema.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness4/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's straightforward purpose (3 required parameters, 100% schema coverage, simple flat structure), the description is complete. It compensates for the missing output schema by describing the return value (comment with assigned ID), and annotations cover the behavioral safety profile.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, providing detailed descriptions for objectType, objectId, and content. The description repeats the enum values and required field status, which adds no semantic value beyond the schema. With complete schema coverage, the baseline score of 3 is appropriate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description opens with a specific verb ('Creates') and clearly identifies the resource (comment) and its attachment targets (trace, observation, session, prompt). This effectively distinguishes it from sibling creation tools like create_dataset or create_model by specifying exactly what types of objects comments can attach to.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines3/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description specifies valid objectType values and required parameters, which provides implicit context for usage. However, it lacks explicit guidance on when to choose this tool over alternatives like get_comments (for reading) or when commenting is appropriate versus other actions. It states requirements but not strategic usage context.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior3/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare destructiveHint=true and idempotentHint=false, indicating this is a state-mutating creation operation. The description adds domain context about validation/structuring but does not elaborate on side effects, conflict behavior (what happens if name exists), or persistence details beyond what the annotations convey.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description contains exactly four tight sentences: one for purpose, one for required fields, and two for conditional parameter usage. Every sentence earns its place with no redundant fluff, and the information is front-loaded with the primary action.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness3/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
The description covers categorical and numeric configuration patterns but completely omits the BOOLEAN dataType case mentioned in the schema. Additionally, it does not mention the 'description' parameter (documented only in the schema) or discuss return values, though no output schema exists to require this.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters4/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema description coverage, the baseline is 3. The description adds crucial semantic value by specifying the conditional logic between data types and their associated parameters (categorical vs. numeric configurations), which is essential for correct invocation but not captured in the flat schema structure.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool 'Creates a score config definition' with the specific purpose of validating or structuring future scores. The verb and resource are unambiguous, and it distinguishes from sibling tools like get_score_config or update_score_config by focusing on the creation aspect.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines3/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides conditional usage guidance for parameters (e.g., 'For categorical configs, categoriesJson should be...' and 'For numeric configs, minValue and maxValue are optional'), which helps users understand when to use specific parameters. However, it lacks explicit guidance on when to use this tool versus alternatives like update_score_config.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior4/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations indicate destructiveHint=true and idempotentHint=false. The description adds valuable behavioral context not in annotations: automatic 'latest' label management by Langfuse, the append-only versioning behavior, and the return value structure. It confirms the mutation nature implied by annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness3/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The content is front-loaded with the core action, but includes redundancy with the schema (listing required fields that are already in the schema's required array). The structure is somewhat fragmented with format instructions interrupting the flow. The final sentence about required parameters is unnecessary given the schema.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness4/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Despite lacking an output schema, the description compensates by stating the return value includes the 'created prompt version with its assigned version number.' It adequately covers the 5 parameters and explains the complex versioning behavior sufficient for invocation decisions.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters4/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema coverage, baseline is 3. The description elevates this by providing concrete examples (labels: production, staging, latest), format specifications (JSON array for chat type), and clarifying the prompt content structure beyond the schema's basic type definitions.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
Description clearly states the tool 'Creates a new version of a prompt' with specific logic distinguishing new prompt creation from version appending. This effectively differentiates it from sibling tools like get_prompt (retrieval) and update_prompt_labels (metadata updates).
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines3/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description explains the internal versioning logic (existence check) and type selection (text vs chat), but lacks explicit guidance on when to use this versus siblings like update_prompt_labels or delete_prompt. No 'when-not-to-use' or alternative recommendations are provided.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior4/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare destructiveHint=true; description adds crucial human-readable confirmation ('irreversible') emphasizing permanent data loss. No contradictions with annotations. Could add context about whether deletion cascades to related resources or failure modes when openWorldHint applies (IDs don't exist).
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Three efficient sentences with zero waste: purpose front-loaded, safety warning second, parameter requirements third. No filler words or tautologies.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness4/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Adequately complete for a destructive 2-parameter operation. Annotations cover safety profile (destructive, not read-only) and idempotency (false). No output schema exists, so return values need not be explained. Minor gap: could clarify behavior when item doesn't exist given openWorldHint=true.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100% with complete descriptions ('The annotation queue ID. Required.'). Description adds redundant requirement confirmation ('Both...are required') without adding semantic meaning, examples, or relationships between parameters not evident in schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
Clear specific verb ('Removes') and resource ('item from an annotation queue'). Unambiguously distinguishes from sibling create_annotation_queue_item (creates), update_annotation_queue_item (modifies), and get_annotation_queue_item (retrieves).
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines3/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Provides critical safety warning ('irreversible') which guides usage caution, but lacks explicit when-to-use guidance versus alternatives (e.g., when to prefer delete over update_annotation_queue_item) and lacks prerequisite context (e.g., needing valid IDs from list operations).
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior4/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description reinforces the destructiveHint=true annotation by explicitly stating 'This action is irreversible,' providing crucial user-facing context about permanent data loss; this adds value beyond the structured annotations by emphasizing consequence severity.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Three sentences efficiently structured with purpose first, parameter format second, and critical behavioral warning third; no redundant language or extraneous details, with every sentence earning its place.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness4/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a single-parameter destructive operation with comprehensive annotations and no output schema, the description sufficiently covers core functionality, input requirements, and irreversibility; minor gaps include explicit sibling differentiation guidance and behavioral details for edge cases.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema description coverage for traceIdsCsv, the schema already documents the comma-separated format and requirement; the description merely echoes 'Pass a comma-separated list' without adding format examples, validation details, or semantic nuances beyond the schema definition.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description 'Deletes multiple traces in one request' provides specific verb (deletes), resource (traces), and scope (multiple/in one request), clearly distinguishing it from the singular delete_trace sibling present in the tool list.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines3/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
While 'multiple traces in one request' implies bulk operation distinct from the singular delete_trace alternative, the description does not explicitly state when to use this tool versus the singular variant or provide explicit exclusion criteria.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior4/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Description adds critical validation rules (JSON must be valid 'when provided') and explains semantic purpose of sourceTraceId/sourceObservationId (linking back to Langfuse data) that annotations don't provide. Destructive nature aligns with annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Four sentences structured logically: purpose statement, required field emphasis, validation constraints, and relationship context. No redundancy; every clause adds information not present in structured fields.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness4/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Covers the upsert semantics (implied by 'Creates or upserts'), JSON string handling requirements, and Langfuse integration context. Does not mention 'status' or 'itemId' parameters explicitly, though itemId is implied by upsert mention. Adequate for 8-parameter mutation tool.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters4/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema coverage, baseline is 3. Description adds value by specifying JSON validity requirements beyond the type declarations and explaining the Langfuse data lineage semantics for trace/observation IDs. Could explicitly mention itemId's role in upsert semantics and status enum values.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
Clear specific action ('Creates or upserts'), resource ('dataset item'), and constraint ('in an existing dataset'). Distinguishes from sibling create_dataset (creates the dataset itself vs item within it).
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines3/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Implies prerequisite (dataset must exist: 'in an existing dataset') and optionality of fields ('when provided', 'Optional'). Lacks explicit comparison to siblings like create_dataset_run_item or guidance on when to prefer get_dataset_item vs this tool.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior4/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare destructiveHint=true and idempotentHint=false; the description reinforces this with 'irreversible'. Critically, it adds behavioral detail not in annotations: 'and all its run items' clarifies the cascade deletion scope, explaining what collateral data gets destroyed. Could add context about openWorldHint behavior (e.g., error if run not found).
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Four sentences respectively cover purpose, safety warning, usage context, and parameter requirements. Front-loaded with the core action, zero redundancy, and appropriately terse for a destructive operation. Every sentence earns its place.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness4/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the destructive nature and lack of output schema, the description adequately covers irreversibility and cascade behavior. Annotations cover safety profile. Minor gap: does not address openWorldHint implications (e.g., behavior when dataset/run doesn't exist) or return value structure.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100% with both parameters fully documented. The description states 'Both datasetName and runName are required,' which merely confirms the schema's required array and property descriptions without adding semantic depth about format or lookup behavior. With complete schema coverage, baseline 3 is appropriate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description explicitly states 'Deletes a dataset run and all its run items'—a specific verb (deletes) with clear resource (dataset run) and scope (including cascade to run items). This distinguishes it from sibling tools like delete_dataset_item (which targets individual items) or delete_model.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines4/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Provides clear usage context ('Use this to clean up experiment runs you no longer need') and warns of consequences ('This action is irreversible'). However, it lacks explicit 'when not to use' guidance or alternative suggestions (e.g., no mention of using get_dataset_run first to verify existence).
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior3/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Adds valuable behavioral context not in annotations: the 500-trace scan limit and response structure (errorCount, timestamps). However, fails to explain why the tool is marked destructiveHint:true and readOnlyHint:false, which is confusing given the 'get'/read-oriented description.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Five sentences with zero waste: purpose first, then implementation limits, response format, parameter optionality, and usage guidance. Front-loaded and efficiently structured.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness4/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Comprehensive coverage including scan limits, response contents (compensating for missing output schema), and parameter behavior. Minor gap: does not clarify the destructive nature of the operation or potential rate limits.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema has 100% coverage (baseline 3). The description adds important semantic detail that parameters are optional and can be omitted for all-time counts, though this appears to contradict the schema's 'required' field.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description opens with a clear specific verb ('Returns') and resource ('ERROR-level traces'), and explicitly distinguishes from sibling tool 'find_exceptions' by stating this is for 'quick health signal' before drilling into individual traces with that alternative.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines5/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Provides explicit guidance on when to use ('quick health signal') versus when to use the alternative ('drilling into individual traces with find_exceptions'). Also clarifies parameter optionality behavior ('Omit them to count errors across all time').
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior4/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations mark this as destructive (destructiveHint=true), but description adds critical context: 'completely replaces the existing label set' (clarifies replacement vs append semantics) and the reserved 'latest' label warning. Also explains empty string behavior for removal.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Five sentences front-loaded with purpose statement. Every sentence adds distinct value: purpose, replacement semantics, reserved label warning, required fields clarification, and empty string behavior. Zero waste.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness4/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
With destructive annotations, 100% schema coverage, and no output schema, the description adequately covers the operation's scope, constraints, and side effects. Missing only error handling details (e.g., prompt not found), which is minor.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100% with all parameters well-documented. Description reinforces required status and empty string behavior, but primarily mirrors schema content. Baseline 3 is appropriate when schema carries the descriptive burden.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
Clear specific verb ('Replaces') with resource ('labels') and scope ('specific prompt version'). Distinguishes from sibling tools like create_prompt (creates new prompts), delete_prompt (removes prompts), and get_prompt (retrieves) by focusing specifically on label management for existing versions.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines4/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Provides explicit constraints: 'The 'latest' label is reserved and managed by Langfuse — do not include it' (when-not guidance) and 'supply an empty string to remove all labels' (special usage pattern). Lacks explicit comparison to alternatives like create_prompt, but provides clear operational constraints.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior4/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
While annotations confirm destructiveHint=true and readOnlyHint=false, the description adds critical behavioral constraints: the irreversible nature of the action and the business logic distinction between custom and Langfuse-managed models. It does not contradict the openWorldHint or idempotentHint annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness4/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Five to six sentences with minimal waste. The core action is front-loaded. Slight redundancy exists between 'Langfuse-managed models cannot be deleted' and 'Only custom models you created can be deleted,' though this serves emphasis for a destructive operation.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness4/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Complete for a single-parameter deletion tool. Covers permission boundaries (custom vs managed), irreversibility warning, and override strategy. Absence of output schema is acceptable as the success/failure semantics of a delete operation are implicit.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters3/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
With 100% schema description coverage, the schema already fully documents modelId as required. The description states 'modelId is required' which merely duplicates the schema's required flag and description, earning baseline score 3.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
The description opens with a specific verb and resource ('Deletes a custom model definition'), immediately clarifying scope. It distinguishes itself from sibling tools by specifying 'custom model' and contrasting with 'Langfuse-managed models,' helping the agent select correctly among create_model, get_model, and list_models.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines5/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Explicitly defines when NOT to use ('Langfuse-managed models cannot be deleted') and provides a clear alternative ('To override a Langfuse-managed model, create a new custom model'). This directly guides the agent toward create_model for the override scenario instead of attempting this deletion.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior4/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already mark destructiveHint=true and idempotentHint=false. The description adds crucial context: specific deletion scope (ALL versions vs labeled vs specific number) and explicitly states 'irreversible'. This explains *what* gets destroyed under different conditions, going beyond the binary safety flags.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Information-dense structure using bullet points for the three behavioral modes. Every sentence earns its place: purpose statement, filter behavior breakdown, required field reminder, and irreversibility warning. No redundancy.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness3/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Covers deletion modes and irreversibility well, but there's unresolved tension: the schema marks all 3 parameters as required while the description describes label/version as optional filters (to be 'omitted'). The description doesn't clarify this discrepancy, leaving ambiguity about the actual invocation contract.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Parameters4/5
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema has 100% coverage (baseline 3). The description significantly adds meaning by explaining the interaction logic between parameters—specifically that label and version function as optional filters despite being schema-required, and the consequences of omitting them. This semantic mapping between parameter presence and deletion scope is essential.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Purpose5/5
Does the description clearly state what the tool does and how it differs from similar tools?
Clearly states the action ('Deletes prompt versions') and target resource ('promptName'), distinguishing it from sibling tools like create_prompt, get_prompt, and update_prompt_labels. The specific focus on 'versions by name' clarifies scope.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Usage Guidelines4/5
Does the description explain when to use this tool, when not to, or what alternatives exist?
Excellent coverage of behavioral modes based on parameter combinations (omit both/supply only label/supply only version). Explicitly notes 'promptName is required' and warns 'This action is irreversible', providing important guardrails. Could explicitly contrast with update_prompt_labels but the filter logic serves as strong implicit guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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