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

Annotations already declare read-only and non-destructive behavior. The description adds meaningful context by explaining the verification covers both authenticity and integrity, and reveals that the key is public, making this a convenience wrapper rather than a privileged operation. Slight gap: no mention of return or failure behavior, but the read-only hint lowers 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.

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

The description is two sentences with no filler. The core action is front-loaded, and the caveat about not needing the endpoint is a useful, efficient addition.

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 one-parameter read-only verifier with no output schema, the description fully explains what the tool checks and why it exists. The only missing piece is the exact return shape, which is a minor gap given the simplicity of the tool.

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 describes the single parameter as 'the compact JWS' with 100% coverage, so the description adds no additional parameter-level meaning. Baseline 3 is appropriate because the schema carries the full burden.

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 states a specific verb and resource: 'Check whether an attestation was really issued by this site and has not been altered.' This clearly distinguishes it from sibling tools like attest or deliberate, which create or reason about attestations rather than verifying 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?

The description explicitly notes that the endpoint is not necessary because the key is published and the algorithm is standard EdDSA, positioning the tool as a convenience. This gives the agent clear context on when this endpoint can be bypassed, though it stops short of naming an alternative tool.

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