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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is covered. The description adds a genuinely useful constraint not present in the annotations: it refuses to revoke the currently-authenticating key, which changes agent behavior. It could go further on consequences (e.g., whether revoked keys are recoverable).

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 short sentences, zero filler, with the core action stated first and the important constraint second. Nothing is wasted or buried.

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, no-output-schema tool whose annotations already carry destructiveness and idempotency, the description covers the essentials plus a key behavioral guard. The main remaining gap is what happens on failure or whether revocation is reversible.

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?

With a single parameter at 100% schema description coverage, the schema already documents key_id and its origin (key_list). The description adds no additional meaning about the parameter, 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?

The description uses a specific verb ("Revoke") plus resource ("an API key"), so an agent immediately knows this is a deletion operation. It is clearly distinguishable from siblings like key_create and key_list, but it does not explicitly contrast itself with them.

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?

Usage is implied: revoke a key you no longer want, using a key_id that the schema notes comes from key_list. There is no explicit when-to-use/when-not guidance or statement of alternatives, and no mention of whether revocation is permanent or recoverable beyond the self-key exclusion.

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