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

Discloses behavior an agent cannot get from annotations: the plaintext token is returned exactly once and must be handed to the user for secure storage, there is a 20-active-key cap, and the call requires the api_keys:write scope. These are precisely the failure modes (losing the token, hitting the quota, missing auth) that matter for this mutation.

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?

Four short sentences, front-loaded with what the tool produces and the one-time-secret warning before the quota and permission notes. 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 still explains the return value (plaintext token, delivered once) and adds prerequisites and limits. An agent has everything needed to call this correctly and handle the result safely.

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 single parameter is fully documented in the schema (label, max 80 chars) at 100% coverage, so the schema carries the load. The description adds no further semantics about the name field, which matches the baseline 3 for high-coverage schemas.

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 ('Mint a new model API key'), plus the concrete token format, endpoint, and auth scheme. This is unmistakably distinct from siblings like create_api_credit_checkout or create_company.

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?

Explicitly constrains usage ('Use it only when the user asks for a new key') and rules out a likely confusion by noting it does not add prepaid credits. However, it never names the relevant alternatives (list_api_keys for inspection, revoke_api_key for cleanup), so routing is solid but not fully specified.

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