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

Annotations declare readOnlyHint=false and destructiveHint=false, consistent with a token-creation tool. The description adds meaningful behavior beyond that: the token is single-use, expires in an hour, and yields a long-lived credential on the runner, plus the exact return shape. Not contradicted, but it does not cover permission requirements or failure modes.

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 action and scope, then the lifecycle behavior, then the return shape. No filler or redundancy.

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 present, the description compensates by enumerating the return fields {owner, token, expiresAt, gluecronUrl}. Combined with the single-use and expiry semantics and the owner scoping rules, an agent has 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?

Schema description coverage is 100%, so the baseline is 3, but the description adds real meaning to the owner parameter by enumerating valid value classes (username, owned/admin'd org, or 'platform' as a site admin) beyond the schema's terse 'Username, org slug, or platform'. Labels is left to the schema, which documents it adequately.

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 ('Create a one-time CI runner registration token') with explicit scope for the owner argument, clearly distinguishing it from siblings like gluecron_list_runners and gluecron_revoke_runner. An agent can identify what this produces without opening the 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?

Explains the context of use: a runner started with RUNNER_REGISTRATION_TOKEN registers once and the owner's CI then runs on it. It clarifies which owner values are acceptable, including the site-admin-only 'platform'. It stops short of explicitly naming alternative tools or when-not-to-use conditions, so it falls just under a 5.

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