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

Annotations only declare the generic write profile (readOnly=false, destructive=false, idempotent=false). The description goes well beyond that with the single most important behavior of this call: the secret is returned once and cannot be read again, so it must be handed to the user immediately. It also discloses the credential's blast radius (all projects), which the annotations cannot express.

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, each earning its place: what is created, its scope, and the one-time-secret handling requirement. The most operationally critical fact (irrecoverable secret) is given prominent placement rather than 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?

With no output schema, the description correctly takes on the burden of describing the return value (the key appears only in this result). Combined with the scope disclosure and the store-as-secret instruction, an agent has everything needed to call this and to handle the response 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?

Schema coverage is 100% for the single `name` parameter, including an example value, so the schema already carries the parameter meaning. The description adds no further guidance on naming or on how the name relates to the returned key, which is acceptable but no better than the baseline.

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?

"Create an API key for the REST API" gives a specific verb plus resource, and the parenthetical auth scheme (Bearer sc_…) pins down exactly what artifact is produced. It does not name or contrast with adjacent tools (list_api_keys, revoke_api_key), so an agent must infer the distinction from the verb.

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 description supplies decision-relevant scope ("It reaches every project of the account"), which helps an agent judge whether to mint an account-wide credential. However, there is no explicit when-to-use guidance versus list_api_keys/revoke_api_key and no stated prerequisites or warnings about creating a broad-scope secret.

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