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

Annotations already indicate destructiveHint=true, and the description adds valuable context: the key stops authenticating immediately on the next request, and permission scoping is specified. This goes beyond the annotations without contradicting them, though it does not mention whether the action can be undone or any side effects.

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?

The description is extremely concise: two sentences with no redundant wording. It front-loads the core action and then adds essential details about timing and permissions. Every sentence earns its place.

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 simple one-parameter tool with annotations, the description covers purpose, effect, and permission context. It lacks an explicit comparison to rotate_api_key but is otherwise sufficient for an agent to understand the tool's role. The absence of an output schema is acceptable given the tool's simplicity.

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 schema fully documents the sole parameter keyId as a UUID, providing 100% coverage. The description adds no additional parameter format information, but the permission note ('Owner anywhere, editor on own keys') gives some context about authorization. Baseline 3 is appropriate since the schema already handles 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?

The description clearly states the action ('Manual hard revoke') and resource ('API key'), and explains the immediate effect ('stops authenticating on the next request'). It distinguishes from sibling tools like rotate_api_key by emphasizing 'hard revoke' and 'manual', making the intent unambiguous.

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 usage is implied: use when you need to permanently revoke an API key. Permission rules ('Owner anywhere, editor on own keys') provide context, but there is no explicit guidance on when to use this tool versus alternatives like rotate_api_key or revoke_project_token, nor any conditions for when not to use it.

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