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

Goes well beyond the annotations: it discloses the auth requirement (current key), that the new key is displayed only once, that the old key is invalidated immediately, and that no request body is needed. That is exactly the operational context an agent needs before calling a destructive, non-idempotent tool.

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, front-loaded with the action and followed by the trigger condition, auth requirement, and the one-time return of the new key. No filler.

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?

With no output schema, the description supplies the crucial return-value fact (new key shown once) and the side effect (old key dies immediately). Nothing needed to call this correctly 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?

Zero parameters, so the schema carries nothing to interpret. The description explicitly closes the loop with 'No body is required,' which is the only parameter-relevant fact worth stating.

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?

States a specific verb+resource ('Replace your API key') and names the underlying endpoint it wraps. No sibling tool performs credential rotation, so the distinction is 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?

Gives a clear trigger condition ('if it may have leaked') plus the prerequisite that the caller must authenticate with the current key. It does not name an alternative, but no sibling offers a comparable operation, so nothing is left dangling.

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