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

Annotations already establish destructiveHint=true and idempotentHint=true, lowering the bar. The description adds meaningful context beyond annotations by stating that an API key is required and that revoking the current key will fail subsequent calls. This is exactly the kind of behavioral warning an agent needs.

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?

Two compact sentences with no filler. The primary purpose is stated first, followed by the key prerequisite and an important side-effect warning. Every sentence adds necessary information.

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 destructive action with a full output schema and annotations covering destructive/idempotent behavior, the description is complete. It covers required authentication, identifier source, and a critical failure mode, so an agent has everything needed to invoke it correctly.

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 for parameters is 100%, so the schema already documents key_id. The description reinforces that key_id comes from list_api_keys, which adds minor context about the value's provenance, but does not provide additional format, constraints, or usage semantics beyond what the schema states.

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 states a specific action ('Revoke'), a resource ('API key'), and the exact identifier source ('key_id from list_api_keys'). It clearly distinguishes the tool from sibling tools like create_api_key and list_api_keys without requiring deeper inspection.

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: the key_id must come from list_api_keys and an API key is required for the call. It does not explicitly name alternatives or state when not to use this tool, but the context is sufficient to guide correct invocation and differentiate from list/create operations.

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