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

Annotations already declare destructiveHint=true, idempotentHint=true, and readOnlyHint=false, so the safety profile is covered. The description adds two things beyond that: the effect is permanent ('for good', stronger than mere destructiveness) and other keys are unreachable via this tool. It does not say whether the current session or in-flight requests survive, nor what the response confirms.

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, action and irreversibility front-loaded, with no filler. The second sentence ('Other keys are managed only by the person') is useful but slightly colloquial and takes a moment to parse as a scope exclusion.

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 zero-parameter, fully annotated destructive tool with no output schema, the description covers what it does, that it is permanent, and what it does not cover. The remaining gap is post-call behavior — whether the key dies immediately and what the caller sees afterwards — which matters for an irreversible action but is a minor omission here.

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 accepts no parameters at all, so there is nothing for the description to disambiguate. Baseline is 4 for a zero-parameter tool; the description correctly makes clear the target is implicit (the calling key) rather than something the agent must supply.

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?

A specific verb (revoke) plus a precisely scoped resource: the API key making the current call, not keys in general. The scope qualifier 'making this call' plus 'for good' lets an agent distinguish this from a generic key-management operation without opening any 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?

Usage is implied by the resource scoping (this is the self-service path for the caller's own key) and the closing sentence signals other keys are out of scope for the API. However, there is no explicit when-to-use/when-not guidance, no precondition such as confirming with the user first, and no warning that this is the correct tool only when the caller wants its own key retired.

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