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

Annotations already declare destructiveHint=true, readOnlyHint=false and idempotentHint=true, so the safety profile is structured. The description still adds real value: permanence and non-reversibility in plain language and a 'confirm intent before calling' instruction, which is the operational consequence an agent needs. It stops short of stating what a revoked key loses access to or what the response looks like.

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, front-loaded blocks with the destructive verb first and the alternative second. There is mild redundancy between 'Use if a key leaked' and 'Use when a Registry API key leaked or is no longer needed', but no meaningful padding.

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 destructive tool with no output schema, the definition covers the trigger, the exclusion, the permanence, the env-var fallback and the confirm-first posture. Only the post-revocation effect and any error conditions are unstated, which is a minor gap given the annotation coverage.

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 coverage is 100% with a single documented parameter that already explains the env-var override. The description's 'Pass api_key, or set REGISTRY_API_KEY' restates the same fallback, adding no new syntax or format detail. Baseline 3 is appropriate when the schema carries the parameter semantics.

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: 'PERMANENTLY revoke a Registry API key (the one presented)'. It also names the sibling it is not (registry_key_info for inspection), so an agent can distinguish intent without opening either 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?

Gives explicit triggers ('a key leaked or is no longer needed and must be disabled permanently') and an explicit exclusion with the alternative named ('Not for inspecting a key (use registry_key_info)'). Nothing about selection 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.