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

Annotations already declare readOnlyHint=true, destructiveHint=false, establishing it as a safe read operation. The description adds valuable context: explains the return value structure for matches and the nuanced meaning of a false result (no attestation vs. tampering), and discloses that no API key is required. This exceeds what annotations provide, though it doesn't mention potential rate limits or error handling.

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 about 6 sentences. It is front-loaded with the core purpose and usage hint. While every sentence is informative, some minor redundancy ('the tool that actually returns a verdict') could be trimmed. Still, it is efficient 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's simplicity (1 parameter, no output schema, read-only annotations), the description covers the essential aspects: input type, return value for matches and misses, authentication requirements, and usage guidance. It does not detail error responses or rate limits, but for a query tool, this is reasonably complete.

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 schema already documents the hash parameter with 100% coverage (pattern, type, description). The description adds further meaning: 'Hash the bytes you actually hold — if they were modified after attestation, the digest won't match any record and `verified` comes back false.' This clarifies the consequence of incorrect input, adding value beyond the schema's description.

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's purpose: 'Ask Kamy whether a SHA-256 digest has an attestation on record — the tool that actually returns a verdict.' It uses a specific verb (verify) and resource (attestation by digest) and distinguishes itself from the sibling tool verify_pdf_signature by explicitly noting the difference in input type.

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: 'Takes a digest, not a file: if what you hold is a PDF, run verify_pdf_signature over the bytes first and pass the sha256 it gives you.' This clearly states the input requirement and points to an alternative tool for PDFs, helping the agent decide when to invoke this tool versus verify_pdf_signature.

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