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

Annotations declare destructive=true, and the description adds detail beyond that: 'permanently' and 'the key will immediately stop working' quantify the blast radius and timing. It also adds an authorization constraint ('You must own the key') that annotations cannot express.

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, no filler. Effect is front-loaded ('permanently', 'immediately stop working') before the prerequisites and discovery hint.

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 destructive tool with no output schema, the description covers effect, permanence, ownership requirement, and how to obtain the input. Nothing an agent needs in order to call it safely is missing.

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?

Only one parameter, and the schema already documents it (keyId, from list_api_keys) at 100% coverage. The description reinforces the provenance of the ID and the ownership requirement, adding marginal value on top of the 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?

Specific verb (revoke) plus resource (API key) plus scope qualifier ('permanently'). An agent can distinguish this from provision_api_key or list_api_keys without opening the schema. No ambiguity.

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?

Explicit prerequisites ('You must own the key') and explicit discovery route ('Use list_api_keys to find the key ID'). Names the sibling that supplies the required input, which is exactly the routing an agent needs.

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