attest-mcp-server

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

With no annotations provided, the description carries full burden and does well by explaining the tool's behavior: it performs an 'offline-style' check (implying no network calls beyond JWKS fetch), requires org_id to fetch JWKS, and returns validity, decoded claims, and warning details. It doesn't mention rate limits, auth requirements, or error conditions, but provides substantial operational context.

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 perfectly front-loaded with the core purpose in the first clause, followed by usage guidance and behavioral details. Every sentence earns its place by providing distinct value: purpose, when-to-use, alternative tool, requirements, and return values. No wasted words.

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 2-parameter tool with no annotations and no output schema, the description provides excellent context about purpose, usage, and behavior. It explains what the tool returns (validity, decoded claims, warning details) which compensates for the missing output schema. The only minor gap is lack of error case documentation.

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 description coverage is 100%, so the schema already documents both parameters thoroughly. The description adds minimal additional context about org_id ('needed to fetch JWKS'), but doesn't provide syntax, format, or validation details beyond what the schema provides. Baseline 3 is appropriate when schema does the heavy lifting.

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 specific action ('perform an offline-style validity check'), the resource ('one credential'), and the method ('using the org JWKS fetched from Attest'). It explicitly distinguishes from sibling 'check_revocation' by stating this is for validity checks while that is for revocation-only checks.

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 guidance on when to use this tool ('to inspect a token before acting on it or when debugging why a credential was rejected') and when not to use it ('for revocation-only checks use check_revocation instead'). It names the specific alternative tool and clarifies the different use cases.

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