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

Annotations already flag destructiveHint=true and idempotentHint=false; the description adds the two facts an agent most needs beyond that: the old secret is invalidated immediately (irreversible break for existing consumers) and the new secret is returned only once (must be captured on this call). It stops short of permission/scope requirements, so not a 5.

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 sentences with zero filler; the destructive consequence and the one-time return are both front-loaded and each earns its place.

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 usefully tells the agent the response carries the new secret and only once. For a one-param destructive tool whose safety profile is annotated, that covers nearly everything needed to call 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?

Only one parameter, and the schema documents it fully at 100% coverage ('API key ID'), so the description adds nothing about the id argument. Baseline 3 applies since the schema carries the full burden.

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 and resource ('Issue a new secret for an API key') plus the immediate consequence ('invalidate the old one'). Clearly distinct from siblings like update-api-key, get-api-key, and delete-api-key.

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 warning that the old secret is invalidated immediately implies this is a last-resort rotation action, but it never says when to choose this over update-api-key or delete-api-key + create-api-key, nor lists prerequisites or required permissions.

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