whois

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

No annotations are provided, so the description must disclose behavioral traits. It mentions cost and wallet requirement, but does not describe error behavior, rate limits, or what happens if the domain is not found. The RDAP protocol is mentioned, but response format or potential failures are omitted.

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?

The description is a single, front-loaded sentence that includes cost, protocol, and returned data without unnecessary words. Every element serves a purpose, making it highly efficient.

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?

Given no output schema, the description adequately lists the returned fields and mentions the protocol. However, it lacks details on error scenarios or the structure of the response (e.g., JSON format). For a simple lookup tool, this is acceptable but not fully complete.

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?

The single parameter 'domain' has 100% schema coverage, but the description adds value by clarifying it must be a registrable domain with an example (example.com). This goes beyond the schema's basic 'Domain name' description.

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 that the tool provides domain registration data via RDAP, listing specific data items like registrar, creation/expiry dates, status, and nameservers. This distinguishes it from sibling tools like dns, tls_cert, and http_check, which handle different aspects.

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 includes cost and wallet requirement but does not provide explicit guidance on when to use this tool versus alternatives like dns or search. Usage context is implied by the focus on registration data, but no when-not or alternative recommendations are given.

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