Missive MCP

Server Quality Checklist

Profile completionA complete profile improves this server's visibility in search results.

Latest release: v0.1.0
Disambiguation5/5
Each tool targets a distinct resource and action, with clear naming and descriptions that prevent confusion even among similar functions like creating drafts vs. messages.
Naming Consistency5/5
All tools follow a consistent 'missive_verb_noun' pattern in lowercase snake_case, with verbs like create, get, list, update, merge, and help used uniformly.
Tool Count4/5
36 tools is high but justified by the breadth of Missive's domain (contacts, conversations, tasks, labels, teams, etc.); however, it exceeds the typical 3-15 range for well-scoped servers.
Completeness2/5
The server systematically lacks delete tools for all entities, leaving a significant lifecycle gap. While intentional for safety, it limits agents' ability to fully manage resources.
Average 4.2/5 across 36 of 36 tools scored. Lowest: 3.6/5.
See the Tool Scores section below for per-tool breakdowns.
- No community issues in the last 6 months
- 4 commits in the last 12 weeks
- Last stable release on June 26, 2026
- No critical vulnerability alerts
- No high-severity vulnerability alerts
- No code scanning findings
- CI is passing
This repository is licensed under MIT License.
This repository includes a README.md file.
No tool usage detected in the last 30 days. Usage tracking helps demonstrate server value.
Tip: use the "Try in Browser" feature on the server page to seed initial usage.
Add a glama.json file to provide metadata about your server.
If you are the author, simply .
If the server belongs to an organization, first add glama.json to the root of your repository:
```
{
  "$schema": "https://glama.ai/mcp/schemas/server.json",
  "maintainers": [
    "your-github-username"
  ]
}
```
Then . Browse examples.
Add related servers to improve discoverability.

How to sync the server with GitHub?

Servers are automatically synced at least once per day, but you can also sync manually at any time to instantly update the server profile.

To manually sync the server, click the "Sync Server" button in the MCP server admin interface.

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

Behavior3/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, which the description supports accurately. The description adds details about pagination behavior (cursor-based, no offset) and optional organization filtering, contributing beyond annotations. However, it does not disclose rate limits or auth requirements.
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 concise sentences that immediately state the purpose and ordering, then cover filtering and pagination. No wasted words; information is 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?
With 10 parameters and no output schema, the description covers ordering, filtering, and pagination well. However, it lacks details about the return structure (e.g., fields in each task object). Given complexity, this is a notable gap.
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 description coverage is 100%, so baseline is 3. The description adds value by clarifying pagination mechanics ('there is no offset') and noting that `organization` is optional with a default. This extra context raises the score above baseline.
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 lists tasks with ordering by last activity. It distinguishes from siblings like missive_get_task (single task) and missive_create_task. However, it does not explicitly differentiate from other list tools like missive_list_conversations, though the mention of task-specific filters helps.
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 filtering options and pagination with `until` and notes no offset. It provides some guidance on how to use the tool but does not specify when to use this tool versus alternative tools (e.g., missive_get_task for a single task) or when not to use it.
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?
Beyond the readOnlyHint annotation, the description adds significant behavioral context: merged conversations return a different id, and guest access returns minimal fields. This helps the agent anticipate edge cases.
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 concise sentences, each adding distinct value: core action, merged behavior, guest limitation. No redundant or filler 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?
Lacks output schema, but description covers key behaviors. However, for a retrieval tool, more detail on the full response structure would improve completeness.
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 schema covers the parameter fully (100% coverage). The description adds no additional meaning to 'conversation_id' beyond what's in the schema, so 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 clearly states the verb 'Fetches', the resource 'single conversation', and the HTTP method. It explains key behaviors (merged conversation, guest access), making purpose unambiguous and distinguishing it from sibling tools like missive_get_message.
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 tool vs alternatives. While the description hints at special cases (merged, guest), it lacks a direct statement of context or exclusions.
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 readOnlyHint=true. Description states 'Fetches', which is consistent. No additional behavioral traits are disclosed beyond what annotations provide, so description adds minimal value.
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?
Single sentence with no extraneous words. Front-loaded with verb and resource. Every word earns its place.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness5/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given tool simplicity (1 param, no output schema), description is complete. It explains purpose and parameter sufficiently for correct selection and 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 parameter description 'ID of the response to fetch.' Description adds context 'canned reply template' but adds no new syntax or constraints beyond schema. Baseline 3 as schema does the work.
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 verb 'Fetches', resource 'single response (canned reply template)', and mechanism 'by its ID'. Distinguishes from sibling missive_list_responses which lists all responses.
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 tool versus alternatives. While context implies use when a specific response ID is known, the description lacks any when-to-use or when-not-to-use information.
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 discloses behavioral traits beyond the readOnlyHint annotation: it lists supported parameters like search, order, limit (max 200), offset, modified_since, include_deleted. This provides functional boundaries. No contradictions 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?
Two sentences: first sentence states purpose and requirement; second lists parameters and read-only hint. Very efficient, front-loaded, no fluff or 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?
Given no output schema, the description does not indicate return structure (e.g., array of contact objects, pagination info). It also omits error cases (e.g., missing contact_book). For a list operation with 7 parameters, it is moderately complete but could add output hints.
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%, so the description's parameter enumeration adds little new meaning. It restates the schema's field list without clarifying format, constraints, or interactions beyond what's already defined.
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 verb 'List', resource 'contacts', and context 'in a contact book'. It also mentions requirement for contact_book. However, it does not explicitly differentiate from sibling tools like missive_get_contact, though the list vs single distinction is implicit.
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 notes that a contact_book is required and that the operation is read-only, but lacks explicit guidance on when to use this tool versus alternatives (e.g., missive_get_contact for a single contact, missive_search_contacts if exists). No 'when not to use' or 'see also' references.
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 clearly states it is read-only, matching the readOnlyHint annotation, and adds that a deleted contact returns 404, providing useful behavioral context beyond 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?
The description is two short sentences, front-loaded with the action, and every word adds value without 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?
The description conveys the essential behavior and read-only nature, but lacks explicit mention of the return format (e.g., the contact object), which could be helpful given no output schema.
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 only parameter, contact_id, is described in the schema as 'UUID of the contact to fetch,' and the description adds 'by its UUID' which overlaps. With 100% 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 'Fetch a single contact by its UUID,' using a specific verb and resource, and distinguishes from sibling tools like missive_list_contacts which fetches multiple contacts.
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 implies usage when a UUID is available but does not explicitly contrast with alternatives like missive_list_contacts or provide guidance on when not to use it.
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 provide readOnlyHint=true. The description adds value by detailing the expanded objects (assignee, team), which informs the agent about the response structure beyond the read-only nature.
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?
A single, concise sentence that front-loads the key action and distinguishing details, with no wasted words.
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 simplicity of the tool and the presence of sibling tools for listing tasks, the description adequately covers the tool's purpose. It mentions the expanded objects, though without an output schema, could be more explicit about the return format.
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 a clear description of task_id. The description does not add additional parameter meaning beyond what the schema already provides.
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 verb ('Gets'), resource ('a single task by ID'), and distinguishes from sibling tools like missive_list_tasks by emphasizing 'full details including expanded assignee and team objects'.
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?
No explicit directive on when to use this tool vs. alternatives like missive_list_tasks or missive_update_task. Usage is implied but not contrasted.
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 readOnlyHint=true, and the description reinforces this with a read operation. It adds context about the nature of shared labels ('folder-like, team-shared') and access scope ('in the organizations you can access'), going beyond the annotation.
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 is a single, efficient sentence with front-loaded purpose. Every word adds value: defines shared labels, specifies action, highlights filter and pagination. No 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?
Given the absence of an output schema, the description could mention the return format (e.g., array of label objects). However, it effectively covers access scope, optional filter, and pagination. With read-only annotation and full schema coverage, it is largely complete.
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%, with detailed descriptions for all three parameters. The description summarizes organization as optional and pagination via limit/offset but adds no new parameter semantics beyond what the schema provides.
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 action ('lists') and the resource ('shared labels') with a clarifying explanation ('folder-like, team-shared conversation tags'). This distinguishes it from other list tools like missive_list_teams and missive_list_conversations.
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 mentions the optional organization filter and pagination parameters but does not provide explicit guidance on when to use this tool versus alternatives like missive_list_teams or missive_list_organizations. Usage is implied but not contrasted.
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 declare destructiveHint=false. Description adds token requirement but doesn't disclose other behavioral traits (e.g., what happens on duplicate team names, limits on number of teams).
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, first sentence states purpose, second adds prerequisite and high-level body shape. No unnecessary 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?
Given many optional nested parameters and no output schema, description does not cover important details like defaults, validation rules, or response format. Adequate but not complete for a complex 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?
Description adds meaning beyond schema by clarifying that 'organization' falls back to MISSIVE_DEFAULT_ORGANIZATION and that 'name' is required. Schema coverage is high but nested properties lack descriptions; this guidance aids agent usage.
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 states 'Creates one or more teams in an organization' with a specific verb and resource. It clearly distinguishes from other 'create' tools like create_contacts or create_draft.
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?
Mentions prerequisite that API token must belong to admin/owner, and hints at when to use (creating teams). Does not explicitly state when not to use or compare to alternatives.
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 declare readOnlyHint=true, and the description reinforces this by noting safety guarantees: 'it cannot send email or delete records'. This adds context beyond the annotation, making the tool's behavior transparent. No other behavioral traits (e.g., rate limits, return format) are disclosed, but for a documentation tool this is sufficient.
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 a single, clear sentence that efficiently communicates purpose and content. It is front-loaded with the main action and then elaborates with specifics. It could be slightly more concise, but it avoids unnecessary verbosity. A 4 reflects good conciseness with minimal 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?
For a tool with one enum parameter, readOnly annotations, and no output schema, the description covers the purpose, topic range, safety guarantees, and typical use case. It does not detail the return format or structure of documentation, but that is reasonable for a help tool. Overall, it is adequately complete.
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% (the only parameter 'topic' is fully described with enum, default, and description). The description does not add additional meaning beyond what the schema provides; it merely lists some topics in the text. Baseline 3 is correct because the schema already carries the semantic load.
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 embedded documentation about the Missive MCP server, listing specific content areas like overview, architecture, tool inventory, and safety guarantees. It also gives a concrete use case: 'understand the project or answer what version do I have?' This fully distinguishes it from sibling tools that perform CRUD operations.
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?
The description explicitly says to call this tool to understand the project or check the version, which provides clear guidance on when to use it. It does not explicitly state when not to use it, but given the sibling tools are all action-oriented, the context is sufficient. A 4 is appropriate as it lacks explicit exclusion phrases but still offers strong implicit guidance.
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 only indicate destructiveHint: false. The description adds that creating labels is non-destructive and mentions the fallback for organization. However, it does not disclose other behavioral traits like rate limits, auth requirements, or behavior on duplicate labels.
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 is a single, well-structured sentence that covers the tool's purpose, required parameters, optional parameters, and a default value. Every part adds value without 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?
Given the tool's moderate complexity (array of objects with multiple optional fields), the description is fairly complete. It covers all key aspects but lacks details on return values or error handling, which are not provided by an output schema.
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 schema has high coverage for the outer array but lacks individual descriptions for nested properties. The description compensates by listing all optional fields (color, parent, sharing options) and noting the fallback for organization, adding meaning beyond the raw 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 creates one or more shared labels, specifying their nature as 'folder-like, team-shared conversation tags.' It lists required and optional fields, distinguishing it from sibling create tools.
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?
The description explicitly says when to use the tool (creating shared labels) but does not provide guidance on when not to use it or alternatives. The context of sibling tools makes the purpose clear, but explicit exclusions would improve the score.
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 adds context beyond the readOnlyHint annotation by specifying exactly what data is fetched (headers, body, attachments, parent conversation). This aligns with and supplements the annotation.
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, front-loaded with the core purpose. Every word is valuable, and the structure is optimal.
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 simple one-parameter read-only tool, the description covers purpose, parameter usage, and content returned. While no output schema, the description is sufficiently complete.
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 description adds no new meaning beyond the schema. The baseline of 3 is appropriate as the schema already documents the parameter clearly.
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 verb 'Fetch' and the resource 'Missive messages' with specific details (headers, body, attachments, parent conversation). It also mentions batch fetching, distinguishing it from listing tools.
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?
The description provides explicit usage guidance: pass one id for single message or several ids for batch. While it doesn't explicitly state when not to use, the context is clear enough given the sibling tools.
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 is consistent with the readOnlyHint annotation, stating 'Read-only.' It adds the GET method and parameter distinctions but no additional behavioral traits such as authentication requirements or side effects. With annotations already covering safety, the description provides marginal extra transparency.
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 is two efficient sentences with no redundancy. It front-loads the purpose and immediately provides actionable parameter details, making it easy for an agent to parse and use.
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?
The tool has 4 parameters, all described in the schema. The description covers the key distinctions and required fields. While pagination (limit, offset) is not mentioned, it is detailed in the schema, so the description is largely complete for a read-only listing tool. A mention of pagination behavior would improve completeness but is not critical.
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 description coverage is 100%, so baseline is 3. The description adds value by explaining the semantics of 'kind' (labels for unrelated contacts vs. related contacts) and the fallback mechanism for 'contact_book' (MISSIVE_DEFAULT_CONTACT_BOOK), which goes beyond the schema's descriptions.
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 action ('Lists'), resource ('contact groups or organizations'), and references the HTTP endpoint. It distinguishes between two kinds (group vs. organization), which differentiates usage and sets it apart from sibling tools like missive_list_contacts.
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?
The description provides clear guidance on when to use each value of 'kind' and notes that 'contact_book' is required (or defaults). It does not explicitly state when not to use the tool, but given the absence of similar sibling tools for contact groups, the context is sufficient.
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 context beyond readOnlyHint annotation: specifies GET method, ordering, draft exclusion, pagination method. No contradictions 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?
Two front-loaded sentences with no redundant content. Efficiently conveys purpose, ordering, exclusion, and pagination.
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 ordering, draft exclusion, and pagination. Lacks error/rate limit info but sufficient for a simple read-only tool with good schema coverage.
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 covers all parameters with descriptions (100% coverage). Description restates pagination method for `until` but does not add new information beyond 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?
Clearly states it lists messages in a conversation, with ordering (newest first) and explicit exclusion of drafts. Distinguishes from sibling tools like missive_list_conversation_drafts.
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?
Specifies draft messages are excluded, guiding usage away from this tool for drafts. Mentions pagination with `until`. However, does not explicitly name alternatives 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.
Behavior4/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotation already indicates read-only, and the description adds pagination behavior ('Paginate with `until` = `created_at` of the oldest post from the previous page'). No contradictions; additional context beyond annotation is provided.
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 no wasted words. The first sentence states purpose, the second provides pagination detail. Front-loaded and efficient.
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 is adequate for a list tool. However, it does not mention the structure of the returned posts (e.g., whether full objects or IDs), which could be inferred from sibling tools. Minor gap.
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%, but the description adds semantic meaning to the `until` parameter by explaining its role in pagination, which is not fully captured in the schema description alone.
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 it lists posts in a conversation, specifies ordering (newest first), and provides the HTTP endpoint. This differentiates it from siblings like missive_list_conversation_comments and missive_list_conversation_messages by targeting 'posts' specifically.
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 pagination instructions but does not explicitly state when to use this tool versus alternatives (e.g., when to use missive_list_conversation_messages instead). Usage is implied but lacks exclusion guidance.
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 declare readOnlyHint=true; the description adds contextual behavior: mentions the scope (teams the user has access to) and the optional filter's effects. The redundant 'Read-only' tag adds no new info but does not contradict 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?
Two efficient sentences. First sentence states purpose and output fields; second covers filtering and read-only nature. No wasted words.
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 simple list tool with pagination (inferred from limit/offset params), the description covers the resource, filter, and access scope. It does not explicitly state that results are paginated, but the schema handles that. Minor missing context about the output structure beyond the field 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 description coverage is 100% with detailed descriptions for each parameter. The description repeats the organization filter behavior already present in the schema, adding no new semantic value beyond 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 identifies the verb 'Lists' and the resource 'teams', and specifies the returned fields (id, name, organization, members, observers, behaviors). This distinguishes it from sibling tools like list_organizations or list_users.
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?
The description explains the optional organization filter and its default behavior (default organization or all accessible organizations). However, it does not explicitly contrast this tool with alternatives, such as when to use it versus list_organizations.
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 context beyond the readOnlyHint annotation by stating the tool lists users across organizations the token belongs to and explains the optional filter. No contradictions 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?
Two concise sentences, first summarizing purpose and returned fields, second clarifying filter. No extraneous information; front-loaded and easy to parse.
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 scope, filter, and read-only nature. Pagination details are in schema. No output schema, but description sufficiently explains what is returned. Slightly incomplete without mentioning the return format is a list, but schema implies it.
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 detailed parameter descriptions. The description essentially restates the organization filter behavior, adding no new semantic value beyond what the schema already provides.
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 verb 'lists' and the resource 'users', with specific fields returned (id, name, email, avatar_url, me). It distinguishes from sibling tools like list_contacts or list_teams by focusing on users and token owner 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?
Provides clear context on the optional organization filter and default behavior when omitted. Lacks explicit when-not-to-use or alternatives, but the guidance on filtering is sufficient.
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 declare destructiveHint: false, indicating non-destructive. The description adds useful behavioral details: the default contact_book fallback and supported subfields (starred, gender, infos, memberships). It does not discuss rate limits or auth, but the annotations reduce the burden.
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 efficient sentences cover the core purpose, key behaviors, and parameter hints. No wasted words; 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 is thorough for input details, but it does not mention what the tool returns (e.g., the created contacts or IDs). Since there is no output schema, the description has a gap. A complete description would at least indicate the return type.
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%, so the schema documents the contacts array. The description adds meaning beyond the schema by explaining the body shape, the default contact_book, and listing supported subfields (infos types, memberships). This helps the agent understand the structure without reading every property.
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 'Create one or more contacts,' a specific action on a specific resource. It distinguishes from siblings like missive_get_contact, missive_update_contacts, etc., by focusing on creation.
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?
The description implies when to use this tool (for creating contacts), but lacks explicit guidance on when not to use it or alternatives. However, the sibling tool names provide context for choosing between create and update 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 discloses that the tool never sends messages, warns about sensitive content leakage with quote_previous_message, and explains how conversations are created or appended. This adds value beyond the annotations (destructiveHint: false) by providing safety context. However, it does not cover all potential behaviors like error handling or rate limits.
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 a single, well-structured paragraph that front-loads the key point (does not send). It is concise given the tool's complexity (24 parameters) and includes essential warnings and usage notes without being verbose.
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?
The description covers key behaviors: draft creation, non-sending, channel support, new vs existing conversations, attachment limits, and important warnings. While it lacks output details (no output schema), it provides sufficient context for an AI agent to use the tool correctly.
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 96% schema coverage, the schema already describes most parameters. The description adds meaningful context, such as the warning for quote_previous_message and the explanation of references and conversation. This supplements the schema without redundancy.
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 it creates a draft for manual review/sending and explicitly says it does NOT send. It distinguishes from sending tools by noting send-related parameters are unavailable, and it supports multiple channels, making the purpose specific and unambiguous.
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?
The description implies usage for drafts that require human review, and explicitly states that it cannot transmit messages. However, it does not directly compare to sibling tools like missive_create_message, which sends messages, leaving some ambiguity about when to use each. A brief contrast would improve clarity.
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 declare readOnlyHint=true, and the description confirms 'Read-only.' Beyond that, it adds behavioral details about what fields are returned (id, name, user, etc.), which is valuable context for 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.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
The description consists of two concise sentences: the first states the action and output, the second provides usage guidance. No extraneous information.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness5/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple list operation with only pagination parameters and no output schema, the description covers purpose, use case, returned fields, and safety. It is fully adequate for the agent to use the tool correctly.
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% for both parameters (limit, offset) with clear descriptions. The tool description does not add any parameter-related information, so it meets the baseline for high schema coverage without enhancing it.
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 'lists' 'contact books' and specifies the returned fields (id, name, etc.). It differentiates from siblings like missive_list_contacts and missive_create_contacts by focusing on contact books specifically.
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?
The description explicitly advises to use this tool 'to find the contact_book id required when creating contacts,' providing clear context. It does not list alternatives or when not to use, but the single explicit use case is sufficient given no sibling tool serves the same purpose.
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 readOnlyHint=true, and description adds that guest users only get id and last_activity_at. Also states 'Read-only', reinforcing the annotation. No 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?
Single paragraph but efficient, front-loading the main action and then detailing constraints. Every sentence adds value, though could be slightly more structured with bullet points.
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 filtering requirements, pagination, guest behavior, and fallbacks. No output schema exists, but the description adequately addresses what the agent needs to use the tool correctly.
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% with good descriptions. The tool description adds extra context: requirement for at least one filter, mutual exclusivity, and pagination technique using 'until'.
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 it lists conversations visible to the API-token user, newest activity first. Distinguishes from sibling list tools by specifying the resource (conversations) and the filter requirements.
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?
Explicitly requires at least one mailbox filter, lists all filter options, and notes mutual exclusivity among email/domain/contact_organization. Also explains pagination. Does not explicitly exclude scenarios but provides clear context for use.
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 declares the tool as 'Read-only', which aligns with the annotation readOnlyHint=true. It adds context that it returns id and name, but no additional behavioral traits are needed given the annotation.
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 is two sentences, front-loaded with the core purpose, and contains no unnecessary words.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness5/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple list tool with no output schema, the description explains what is returned (id, name) and how to use the result (to get organization IDs). It is complete for the tool's complexity.
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%, so the schema already documents limit and offset. The description does not add any further meaning to the parameters, meeting the baseline.
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 verb 'lists' and resource 'organizations', and specifies the return fields (id, name). It distinguishes itself from sibling list tools by focusing on organizations.
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?
The description explicitly tells the agent to use this tool to find organization IDs for filtering in other tools. It provides clear context for when to use it, though it does not state when not to use alternatives.
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?
Disclosure beyond annotations: attachments replacement destroys omitted attachments, and external integration responses are immutable. Annotations provide idempotent and destructive hints, but description adds concrete behavioral details.
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, front-loaded with main action, no fluff. Every sentence adds value.
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 update behavior, constraints, and attachment logic well. But no output schema and description does not mention return value or response format, leaving a gap for a 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, description adds meaning: partial update semantics (only included attributes change) and attachment replacement behavior. Clearly explains how the responses array parameter works.
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 verb (update), resource (responses/canned reply templates), and scope (one or more by id). Distinguishes from create_responses sibling.
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 specific guidance: must include id per response, partial update behavior, attachment replacement warning, and explicit constraint that externally created responses cannot be updated. Lacks explicit when-to-use vs alternatives but is clear within its own context.
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 the tool idempotent and non-destructive. The description adds context by explaining the partial update behavior ('only the attributes you include are changed'), which aligns with the annotations and provides additional clarity.
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 is two sentences long, front-loaded with the action, and every word provides value without 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?
The description covers input well but does not mention the output or return value. For an update tool, knowing what is returned (e.g., updated labels or a success indicator) would improve completeness.
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 description elaborates on the single parameter 'shared_labels', clarifying the requirement for an 'id' and the optional nature of other fields. This adds meaning beyond the schema, which only specifies 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 verb 'Updates' and the resource 'existing shared labels', distinguishing it from create operations. It specifies the action precisely.
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?
The description explains how to provide objects with 'id' and that only included attributes are changed, indicating partial update behavior. It implies when to use but lacks explicit when-not-to-use or alternatives.
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 idempotentHint=true and destructiveHint=false, which align with the update operation. The description adds context about required permissions (admin/owner), which goes beyond 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?
The description is three sentences, concise, and front-loaded with purpose. It could be slightly more compact, but it is efficient.
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 two parameters, full schema coverage, and no output schema, the description covers purpose, permissions, and input format adequately. It does not explain return values, which is acceptable without an output schema.
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%, so the schema already explains parameters. The description adds value by explaining how ids are 'comma-joined into the URL path' and that teams must include only changed attributes.
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 'Updates one or more existing teams' and explains the input structure (ids and teams array), distinguishing it from creation or other tools.
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?
It specifies the prerequisite that 'The API token must belong to an admin or owner of the organization', which is helpful. However, it does not explicitly state when to use this tool over siblings like missive_create_teams.
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 only include destructiveHint: false. Description adds important behavioral context: exclusive scoping rule and fallback to default organization. No mention of authorization or side effects, but acceptable for a create tool.
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 concise sentences. First sentence states purpose, second adds critical scoping details. No fluff.
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?
Tool has one parameter (array) and no output schema. Description covers input structure, scoping, and optional fields adequately. Could mention return value, but not 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?
Schema coverage is 100%, so baseline is 3. Description adds value by clarifying the scoping constraint and optionality of title, which goes beyond what the schema provides.
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 it creates responses (reusable canned replies/email templates), which distinguishes it from other create tools like missive_create_contacts. Verb 'creates' and resource 'responses' are specific.
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 scoping rules (organization vs user) and fallback behavior, guiding when to use this tool. However, does not explicitly say when not to use it compared to alternatives.
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 only have destructiveHint: false. The description adds that tasks appear in Tasks view, not Inbox, and clarifies subtask requirements. It does not contradict annotations and provides useful behavioral context.
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, no fluff. The first sentence establishes purpose, the second covers key constraints and defaults. Every sentence adds value and is well-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?
Given no output schema, the description does not explain return values, but it covers all necessary behavioral and parameter context for a create tool. It is complete enough for an agent to use correctly.
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 100% coverage, baseline 3. The description adds meaning beyond schema by explaining defaults (organization), dependencies (subtask requires conversation/references), and usage of parameters like add_users and conversation_subject, earning an extra point.
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 tasks in Missive, specifying three types (standalone task, tasked conversation, subtask). It uses a specific verb-resource combo and distinguishes from sibling tools like missive_create_draft and missive_create_message by focusing on task creation.
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 context on when to create a subtask vs standalone, and notes required parameters like organization. However, it does not explicitly compare to other create tools or state when not to use this tool, leaving some ambiguity.
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 ordering ('newest first') and pagination behavior beyond the readOnlyHint annotation. No contradictions; reinforces safety.
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, no redundant words. Each piece of information is purposeful and front-loaded.
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 core action, pagination, and idempotency. A bit more detail on return format would be helpful but is not critical given the tool's simplicity.
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 covers all parameters; description adds practical pagination guidance for 'until' and 'limit' max 10, enhancing usability beyond raw 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 it lists comments in a conversation, specifying the exact HTTP endpoint. It distinguishes itself from sibling tools by focusing on comments, a distinct sub-resource.
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 pagination instructions using the 'until' parameter and notes the tool is read-only. Does not explicitly compare to alternatives, but the purpose is unambiguous.
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 pagination and ordering details beyond the readOnlyHint annotation. Discloses that operation is read-only, consistent with annotation.
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 no wasted words. Critical information (endpoint, ordering, pagination, read-only) is front-loaded and succinct.
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 list tool with no output schema. Explains how to paginate and what parameters do. Slightly lacking in describing return format, but acceptable.
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 already describes all parameters (100% coverage). Description adds value by explaining the pagination pattern with `until` as a cursor, which is not fully clear from schema alone.
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 it lists draft messages in a conversation, specifies REST endpoint, ordering (newest first), and pagination. Distinguishes from sibling tools like missive_list_conversation_messages by focusing on drafts.
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 pagination instructions and notes read-only nature, which helps in proper invocation. However, does not explicitly guide when to use this vs other list-conversation tools.
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 readOnlyHint=true; description adds that it lists for the authenticated user, mentions optional filtering and pagination, providing extra context beyond annotations 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.
Conciseness5/5
Is the description appropriately sized, front-loaded, and free of redundancy?
Two clean sentences, no waste, front-loaded with purpose and key details.
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 list tool with good annotations and complete schema, the description adequately explains what is returned and basic filtering/pagination. No output schema, but not required for understanding.
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% so parameters are already well-documented. Description adds extra value by noting the default behavior for organization (MISSIVE_DEFAULT_ORGANIZATION) and indicating pagination via limit/offset.
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 it lists responses (canned replies/email templates) for the authenticated user, using a specific verb and resource. It distinguishes from sibling tools like create, get, update.
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 context on optional organization filter and pagination via limit/offset. No explicit when-not-to-use or alternatives, but clear enough for a list 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?
Discloses idempotency and non-destructive nature, consistent with annotations. Adds conditional requirement for 'organization' and explains the API method and behavior (no post/send). Does not contradict 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?
Concise yet informative, front-loaded with main purpose. Uses structured list of actions and clear parameter guidance. Minor redundancy (e.g., idempotent repeated) but no wasted sentences.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness5/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given no output schema and only two parameters, the description covers essential context: operations, parameter structure, conditional requirements, and an API caveat. No gaps that would hinder correct invocation.
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%, but the description adds meaning beyond schema by explaining the one-object-per-id structure, the conditional need for organization, and the idempotent property. Helps agent construct correct requests.
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 'Updates conversation state' and enumerates specific actions (close/reopen, move, assign, etc.), distinguishing it from siblings like missive_create_post by explicitly saying it does NOT create a post or send anything.
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 context on when to use (update state without creating a post) and notes the absence of an archive action, suggesting alternatives. However, it does not explicitly exclude other tools or provide a comprehensive when-not list.
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 idempotentHint=true and destructiveHint=false, which the description aligns with by describing a partial update (non-destructive). The description adds the important behavioral detail that only included fields are changed, which is not in the annotations. No contradictions.
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 is exceptionally concise: two sentences, zero wasted words. The first sentence states purpose and lists fields, the second clarifies the partial update behavior. It is well front-loaded and easy to scan.
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 has 7 parameters (1 required) and no output schema, the description adequately covers purpose and behavioral nuance. However, it does not mention what the tool returns (e.g., updated task object) or error scenarios (e.g., if task_id not found). This is a minor gap for a mutation tool, but annotations partially compensate.
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% with descriptions for each parameter. The description adds value by clarifying the partial update behavior ('Only the fields you include are changed'), which is not evident from individual parameter descriptions. This is a key semantic that helps the agent understand the tool's merge-like behavior.
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 verb 'Updates' and the resource 'a single task's attributes', listing specific fields. It distinguishes from sibling tools like missive_create_task (create) and missive_get_task (read) by focusing on update semantics.
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?
The description implies usage for updating an existing task, but does not explicitly specify when not to use it or suggest alternative tools like missive_get_task for reading or missive_list_tasks for listing. However, the partial update hint ('Only the fields you include are changed') provides clear context for typical usage.
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 adds transparency beyond the annotation (destructiveHint=false) by explaining that the tool creates a simulated inbound message, never transmits externally, and is not an email send. It also notes the fallback behavior for the 'account' parameter.
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 concise, conveying essential information in three sentences. It avoids unnecessary fluff, though could be slightly more structured by separating the warning from the usage notes.
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 complexity (25 parameters, no output schema), the description covers the core purpose, usage constraints, and key parameter details. It does not describe the return value, but the schema and context signals compensate. Overall, it provides sufficient context for correct invocation.
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 input schema already covers all 25 parameters with descriptions (100% coverage), the description adds extra context for key parameters like 'from_field' (required) and 'account' (fallback to default), and clarifies channel-type variations for message fields.
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 it creates an INCOMING message record in a Missive custom channel, and explicitly distinguishes it from sending an email. It names the alternative endpoint (Drafts) and specifies it never transmits externally.
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?
The description starts with 'ADVANCED — custom channels only', providing immediate usage context. It explicitly says when to use (custom channels) and when not to (not for email sending), and directs to the correct alternative for sending emails.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior5/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the destructiveHint annotation, the description details that posts are permanent, visible to all, send notifications, cannot be undone (no delete tool), and can create new conversations. This provides critical behavioral context beyond the binary flag.
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 is concise, starting with the core purpose, followed by the warning and requirement, all in short, clear sentences. Every sentence adds necessary information without redundancy.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness5/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the complexity of 23 parameters, no output schema, and side effects like permanence and notifications, the description covers key behavioral aspects, constraints, and creation logic. It is complete for an agent to understand the tool's impact and requirements.
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 documents all parameters. The description adds a summary of the text/markdown/attachments requirement and conditional new conversation creation, but does not significantly enrich individual parameter understanding beyond 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 it creates a post in a Missive conversation, uses specific verbs like 'inject content and manage conversation state', and distinguishes itself from sibling creation tools by emphasizing its role as the recommended automation method for state changes while leaving a visible trace. The warning about permanence further clarifies its unique purpose.
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?
The description explicitly says when to use this tool ('recommended way for automation to inject content and manage conversation state') and warns about permanence and notifications, implying avoidance for reversible actions. It also states that missing conversation/references creates a new conversation. However, it does not name specific alternative tools for reversible 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?
Annotations already declare readOnlyHint=true. The description adds that normally a single message is returned, but non-compliant senders may yield up to 10. This provides useful behavioral context beyond 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?
Two sentences, front-loaded with the core action. Every word serves a purpose; no fluff.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Completeness5/5
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the tool's simplicity (1 param, no output schema), the description fully covers purpose, parameter format, and edge case behavior. No gaps remain.
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 schema has 100% coverage for the single parameter. The description adds meaning by referencing RFC 5322, providing an example, and clarifying the expected format. This elevates it above the baseline.
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 verb 'Fetch', the resource 'messages', and the criterion 'email Message-ID' (RFC 5322 header). It uniquely identifies this tool among siblings and explains typical return counts (single message, up to 10).
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?
The description implies usage when you have an email Message-ID. It does not explicitly contrast with sibling list tools or provide when-not-to-use scenarios, but the specificity is sufficient for selection.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior5/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description goes beyond the destructiveHint annotation by detailing what happens (messages, comments, entries move), stating it is irreversible, and noting that the returned conversation ID may differ due to potential swapping. This fully informs the agent of behavioral consequences.
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 is concise (three sentences) with the purpose stated first, followed by essential details and caution. Every sentence adds value without fluff.
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?
The description covers the merge process, irreversibility, and possible ID swap, but lacks explicit mention of the return value structure. While the output schema is absent, describing the return format would improve completeness.
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, the description adds context by clarifying the roles of source and target IDs and explaining the optional subject parameter renames the merged conversation, enriching the semantic understanding beyond the schema alone.
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 'Merges one conversation INTO another', providing a specific verb+resource pair. It distinguishes this from sibling tools like 'missive_update_conversations' by emphasizing the merge action and irreversibility.
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?
The description clearly indicates this tool is for merging conversations, but does not explicitly state when not to use it or mention alternative tools. However, the irreversibility warning serves as implicit guidance for cautious use.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Behavior5/5
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description adds significant behavioral context beyond annotations, such as partial update behavior and the array replacement warning, which aligns with the destructiveHint annotation. No contradictions.
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 is concise with three well-structured sentences, front-loading the purpose and method, followed by important behavioral warnings. No unnecessary 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?
The description covers key aspects like partial updates, array replacement, and idempotency, but does not mention the response format or error conditions. Given the complexity and no output schema, it is mostly complete.
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%, but the description adds value by explaining the id requirement and the semantics of partial updates and array replacement, enhancing understanding of the single parameter.
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 updates one or more contacts by UUID, with a specific verb and resource, and distinguishes itself from sibling tools like missive_create_contacts and missive_list_contacts.
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?
The description provides clear context for updating contacts, including the requirement for IDs and warning about array replacement. It does not explicitly list alternatives or when not to use, but the purpose is well-defined.
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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