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

Annotations already declare readOnly, idempotent and non-destructive, so the safety profile is covered. The description adds genuinely useful behavior beyond that: the response never contains a raw secret key, so the agent knows it cannot retrieve credential material here. It doesn't mention pagination or ordering, but for a small key list that is minor.

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 tight clauses: what is returned, then when to use it. Front-loaded with the resource and the security-relevant 'never a raw key' caveat, with no filler.

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?

With no output schema, the description carries the return-value burden and does so by listing label, prefix, scopes, usage totals and last use. What is missing is only secondary: ordering, pagination, and whether the list is scoped to the calling user or the whole account (the title says 'my', the description says 'the account's', a slight ambiguity).

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 coverage is complete, so the baseline is 4 and there is nothing for the description to clarify. The field inventory it provides describes output, not inputs, which is the right place given the empty 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?

Names the resource precisely (the account's API keys) and enumerates the returned fields, so an agent knows exactly what this yields. It does not explicitly contrast with the near-name sibling manage_api_keys or get_api_status, so sibling differentiation is only implied by the 'before revoking or re-scoping' hint.

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?

Gives a concrete when-to-use scenario: call it to identify/name a key before revoking or re-scoping it, which implicitly points at the mutation sibling. It states no exclusions or edge conditions, and does not say what to do if no keys exist or which tool handles the revoke itself.

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