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

Annotations already declare this is a non-read, non-idempotent, non-destructive operation. The description adds genuinely valuable behavior beyond that: the secret is returned once and stored nowhere (so the caller must capture it immediately), and some write scopes require admin/owner authorization. Return format and rate limits are unstated but not critical.

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 sentences, front-loaded with the core action and scope intent, then the ephemeral-secret warning, then the permission caveat. Slightly dense but every sentence carries real information.

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 create tool with no output schema and modest complexity, the description covers the key callouts: intent, minimal-scope principle, one-time secret, and the admin/owner requirement. Nothing essential is missing, though it could note the key lifecycle relative to revoke_an_api_key.

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%, so the schema already documents name, scopes, and expires_in_days with helpful descriptions. The description only reinforces the scope-selection intent and mentions specific write scopes; it adds little parameter meaning the schema does not already carry, so the baseline 3 applies.

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 (make an API key) and scopes its intent to "an agent with no person behind it," which hints at a non-human/service-account key. It does not explicitly contrast with siblings like list_api_keys or revoke_an_api_key, so differentiation is left to the name.

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?

Provides a prerequisite (certain write scopes need an admin or the owner) and a usage context (only the scopes it needs), which is useful. However, it never states when to use this versus alternatives or routine prerequisites like naming conventions.

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