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

With no annotations, the description carries the full burden and delivers useful context: the key algorithm (Ed25519), the concrete publication locations (apir.ai/.well-known/jwks.json and did:web:apir.ai), and the rotation behavior that retired keys remain published for older credentials. It omits any caching, rate-limit, or availability notes, but the disclosed traits are genuinely beyond what a bare signature would convey.

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, front-loaded with the core action, and each adds distinct information (purpose, trust rationale, publication formats, key-retention policy). No filler or restated title text.

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?

There is no output schema, so the description must signal the return shape — and it does, via the JWKS endpoint and did:web identifier. Combined with the absence of parameters, this covers what an agent needs to call the tool correctly, with only minor gaps around response/refresh mechanics.

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 tool takes zero parameters and the schema is empty, so there is nothing for the description to disambiguate. The baseline for a parameterless tool applies.

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 — returning the Ed25519 public keys APIR publishes — so an agent immediately knows what the tool fetches. It does not explicitly name or contrast with the siblings (check_authority, verify_agent), which perform verification rather than key retrieval, so differentiation is inferred rather than stated.

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?

"so a signature can be recomputed offline without trusting any APIR response" clearly implies the use case (offline/independent verification), but no when-not condition or explicit alternative is given. The relationship to sibling verify_agent, which likely performs verification for you, is left to inference.

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