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

Annotations only declare readOnlyHint=false and destructiveHint=false; the description adds substantial context beyond that: the token is returned once, effective access is capped by the caller's current repo access and re-checked on every use, branch protection applies, 'repo' scope is required, and the action is audit-logged. This is exactly the behavioral disclosure a mutation tool needs.

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?

Front-loaded with the core action and scope, then permissions and expiry details. It is dense and long but nearly every clause carries operational meaning; a minor cost is the run-on sentence packing many constraints together.

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 5-param mutation tool with no output schema, the description covers authentication scope, permission model, expiry rules, access capping, and even the return shape ({id, name, repository, permissions, expiresAt, tokenPrefix, token}). Nothing an agent needs to call it 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?

Schema coverage is 100%, so the baseline is 3, but the description adds real meaning: admin and settings are never grantable, runners is read-only, omitted keys default to none, at least one must be read/write, and expires_in bounds (5 min to 1 year) with accepted formats. It reinforces rather than merely repeats the schema.

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 (mint) and resource (fine-grained repository token) with explicit scope: ONE repository, returned once. The scope and single-repo constraint distinguish it from siblings like create_deploy_token, create_runner_registration_token, and get_token without needing to open any schema.

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?

It clearly explains what the token authenticates (REST v2/v3, git over HTTPS, container registry) and the 'repo' scope prerequisite, which implies when to use it. However, it never explicitly contrasts with sibling token tools such as create_deploy_token or get_token, leaving the agent to infer the choice.

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