Fabric Marketplace

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description discloses behavioral traits beyond annotations: it requires no authentication, returns node profile, API key, credits, and setup guidance. It also warns against reuse. Annotations are sparse (readOnlyHint=false, destructiveHint=false), but the description adds value. Minor missing details on error handling, but overall transparent.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single paragraph of six sentences, front-loaded with the main purpose. It is efficient but could be improved with bullet points for post-creation steps. Overall, it is concise and well-structured.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool has 5 parameters, no output schema, and minimal annotations, the description provides a complete picture: purpose, usage guidelines, return values, and follow-up actions. It does not cover error scenarios, but the context is sufficient for an 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.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema already describes all 5 parameters with descriptions (100% coverage). The tool description adds little new parameter semantics; it reiterates the safety confirmation and recommends recovery_public_key, but does not significantly enhance understanding beyond the schema. Baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool 'Create a new Fabric participant identity (node) and receive an API key + 500 free credits.' It uses specific verbs and resources, and distinguishes itself from sibling tools by explicitly stating it is not a credential refresh, login session, or recovery tool, and advises not to use if a node already exists.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides explicit when-to-use and when-not-to-use guidelines, including 'Do not use this if the participant already has a node,' and offers alternatives like 'use fabric_login_session' or 'recovery' when appropriate. It also gives post-creation steps, ensuring clear usage context.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already cover read-only/idempotent/destructive hints, so description adds valuable complementary context: authentication requirements and specific payload structure (IDs, slugs, names, descriptions, examples) that would normally appear in an output schema.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two dense sentences with zero redundancy. First sentence defines operation and return payload; second covers auth prerequisites and integration guidance. Every clause earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Compensates adequately for missing output schema by enumerating return fields. Covers auth and integration patterns relevant to the fabric ecosystem. Could be enhanced with pagination or caching behavior details, but sufficient for a simple registry fetch.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Zero parameters present, establishing baseline score of 4 per scoring rules. Description appropriately focuses on output semantics rather than inventing parameter documentation.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Uses specific verb 'Get' with clear resource 'category registry' and enumerates exact return fields (IDs, slugs, names, descriptions, examples). Distinguishes from sibling fabric_get_nodes_categories_summary by emphasizing 'full' registry versus summary data.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Provides explicit prerequisite 'No authentication required' and usage context 'Use category IDs when creating units/requests' linking to dependent workflows. Lacks explicit mention of alternative tools like fabric_get_nodes_categories_summary for when summaries suffice.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations cover safety profile (readOnly, idempotent). Description adds crucial behavioral context not in annotations: 'No authentication required' and specifics of returned metadata (category/docs/legal URLs), helping the agent understand what data to expect.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two highly efficient sentences. First sentence front-loads the return payload specifics. Second sentence covers auth requirements and usage timing. Zero waste.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a zero-parameter metadata tool, description compensates for missing output_schema by enumerating expected return fields (legal version, API version, URLs) and providing clear workflow positioning. Would be 5 with explicit error condition notes or rate limits.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Zero parameters (baseline 4 per rules). Schema is empty object with additionalProperties=false, fully described by structure. Description appropriately adds no redundant parameter documentation.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Specific verb 'Get' + resource 'Fabric service metadata' with detailed payload specifics (legal version, API version, URLs). The phrase 'before bootstrap' clearly distinguishes it from the fabric_bootstrap sibling, establishing a discovery-phase role.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly states when to use ('before bootstrap') and prerequisites ('No authentication required'). Lacks explicit 'when not to use' or named alternatives, but the temporal positioning relative to bootstrap provides clear contextual guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Adds valuable behavioral details beyond annotations: explicitly states 'No authentication required' and describes the return format (ISO 3166-1/2 codes with examples 'US', 'US-CA'), compensating for the lack of output schema.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three sentences, zero waste: sentence 1 establishes purpose+scope, sentence 2 states auth requirements, sentence 3 documents return format. Perfectly front-loaded and dense with essential information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Comprehensive for a zero-parameter lookup utility: covers purpose, auth constraints, and return value structure (with format standards and examples) despite lack of output schema. Annotations cover safety profile (readOnly, idempotent).

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Zero parameters with 100% schema coverage (trivially). Description correctly implies no inputs are needed through the declarative 'Get' construction. Baseline 4 as per zero-parameter rule.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Excellent specificity: 'Get supported region codes' provides clear verb+resource, and 'for search filters and scope fields' establishes clear scope that distinguishes this from sibling tools like fabric_get_categories or fabric_get_events.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Provides clear context that these codes are intended 'for search filters and scope fields,' indicating when to use the tool. Lacks explicit 'when not to use' or alternative tool names, but the functional context 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.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations declare non-readonly (mutation) and non-idempotent hints. Description adds 'short-lived' qualifier (lifetime behavior) and specific runtime constraint context. 'No authentication required' is slightly confusing given the api_key parameter, but likely means 'no existing session required.' Adds moderate value beyond structured fields.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three sentences, zero waste. Front-loaded with core action (create token), followed by usage condition, then auth prerequisite. Each sentence earns its place with distinct, non-repetitive information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Tool creates session state (annotations confirm mutation) but no output schema exists to describe the returned token structure. Description states a token is created but doesn't hint at the return format or that subsequent tools will use this session. Adequate but not comprehensive given lack of output schema.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% with complete description of api_key ('Fabric API key from bootstrap or key management'). Description mentions the api_key implicitly ('from an API key') but doesn't add syntax constraints or format details beyond schema. Baseline 3 appropriate when schema is comprehensive.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Clear specific verb ('Create') + resource ('short-lived MCP session token') + input source ('from an API key'). Distinguishes from sibling 'fabric_logout_session' (likely the inverse operation) and 'fabric_auth_keys' (manages keys vs consumes them).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicit conditional usage provided: 'Use this when your MCP runtime cannot reliably set Authorization headers.' Identifies the specific technical constraint triggering use. Minor gap: doesn't explicitly mention the alternative (direct header auth) or that this establishes session state for subsequent calls.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations indicate readOnlyHint=false, which aligns with the mutation of creating a new API key. The description adds transparency by stating 'No authentication required' and that it returns a new key. 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.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single, front-loaded sentence with no redundancy. Every clause adds essential information: action, two alternatives, output, and authentication status.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description fully covers the tool's purpose, inputs, and output for a two-path recovery completion. It is sufficient given the schema's detail and the absence of an output schema.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema descriptions are thorough (100% coverage) for code and signature. The description adds value by clarifying the mutual exclusivity ('either the Ed25519 signature... or the 6-digit email recovery code'), which is not explicit in the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states 'Complete account recovery' with the specific methods (Ed25519 signature or email code) and outcome ('Returns a new API key'). It distinguishes from sibling fabric_recovery_start by referencing the challenge_id from that tool.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explains when to use the tool: after recovery start, by providing either a signature or code. It also notes no authentication is required. It could explicitly mention the prerequisite of fabric_recovery_start, but the context makes it clear.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations are all false, providing no hints. Description adds important behavioral context: no authentication required, and explains the response (nonce or recovery code). Does not cover rate limits or failure modes.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, front-loaded with purpose, no waste. Efficiently conveys all necessary information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Tool is simple and description covers purpose, methods, and prerequisites. No output schema needed as response type is implied. Contextual completeness is high given the tool's role in recovery flow.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and parameters are well-documented. Description adds value by explaining which parameters are required per method and constraints like verified email.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Description clearly states it starts account recovery for lost API keys, specifying two methods (pubkey and email). Distinguishes from siblings like fabric_recovery_complete, which is the next step.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Clearly explains when to use (lost API key) and the two methods with prerequisites. Lacks explicit when-not-to-use or alternatives, but context is clear.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.