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

Annotations already declare destructiveHint=true and readOnlyHint=false, but the description adds behavior that annotations cannot express: revocation propagates over roughly a minute, and the action is irreversible. It does not cover authorization requirements or whether an error is returned when the key is already revoked, so it is strong rather than exhaustive.

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 compact sentences, each carrying distinct information: action and identifier source, propagation timing, and irreversibility. The irreversible warning is placed last where it lands as a caution rather than burying the core action.

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 mutation tool with full schema coverage, annotations declaring destructiveness, and no output schema, the description covers everything an agent needs: what it does, where the id comes from, the effect timing, and that it cannot be undone.

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 single key_id parameter is already documented as coming from list_keys. The description repeats the same provenance hint without adding format, validation, or failure-mode semantics beyond the schema, so the 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 and resource ('Revoke an API key') and immediately identifies the tool that supplies the required identifier ('from list_keys'). That alone distinguishes it from sibling tools like create_key, list_keys, and set_spend_limits.

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 gives clear context for invocation by naming list_keys as the source of the key_id, so an agent knows the prerequisite step. It does not explicitly state when not to use it or note that no alternative revocation tool exists, so it falls short of the explicit exclusion guidance a 5 requires.

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