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

The description adds meaningful behavioral detail beyond the annotations: retries with identical inputs return the same durable registration, and the tool never accepts a private key. This complements the idempotentHint annotation and makes the mutation semantics clearer. No contradiction with annotations is present.

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 adding distinct information: the action and inputs, retry semantics, and a security constraint. The most important guidance is front-loaded and there is 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?

The description, combined with rich per-parameter schema descriptions and the output schema, fully equips an agent to call this tool correctly. It covers required inputs, retry safety, and the private-key exclusion without needing to explain return values.

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%, and both parameter descriptions are already detailed. The description adds value by emphasizing that the signature must be canonical base64, produced locally, and that a private key must never be supplied. This helps an agent avoid common misuse.

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?

The description clearly states a specific action and resource: complete an Innerloop registration using a challenge id and a locally produced Ed25519 signature. It is clearly distinct from innerloop_start_registration because it completes rather than starts registration, but it does not explicitly name or contrast sibling tools.

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 gives clear context: this is the registration-completion step, requiring artifacts produced locally and tied to a prior challenge. It also provides important retry guidance, stating an uncertain retry is safe only with the exact same challenge id and signature. It does not explicitly list alternatives or say when not to use this tool.

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