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

With no annotations, the description carries the full burden and does disclose two non-obvious traits: repeat calls are idempotent, and a specific session scope is required. It omits the destructive/irreversible nature of revocation and what happens to requests using the key, so it is strong but not complete.

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 short sentences, action and target front-loaded, with the idempotency and auth facts appended. No filler or repetition.

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 single-parameter mutation with full schema coverage and no output schema, the description supplies the operation, identifier, idempotency and authorization requirement. It stops short of describing the effect of revocation (immediate permanent invalidation, impact on in-flight traffic), which is the only meaningful remaining gap.

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% and the key_uuid property already explains it is the public UUID returned by create_api_key or list_api_keys. The description's 'by uuid' adds no format or sourcing detail beyond the schema, so baseline 3 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?

States a specific verb (revoke), a specific resource (one of the caller's PricklyMails API keys) and the identifier used (uuid). No sibling tool performs revocation, so it is trivially distinguishable from create_api_key/list_api_keys without opening any schema.

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 scope prerequisite ('Requires the api_keys:revoke scope') gates usage and is useful, but there is no explicit statement of when to revoke versus disabling or rotating a key, and no mention of the sibling list_api_keys/create_api_key as the way keys come into existence. Usage is implied by the verb rather than spelled out.

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