whois_lookup

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

With no annotations provided, the description carries the transparency burden. It clearly indicates a read-only lookup and specifies the output fields, which is good. However, it does not mention potential edge cases like invalid domains, response formatting, or network behavior, preventing a perfect score.

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 concise sentence, front-loaded with the tool's purpose and key output details. Every word earns its place, with no redundancy or 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?

For a simple one-parameter lookup tool without an output schema, the description sufficiently conveys the main return values. It could be enhanced with notes on error handling or response format, but overall it supplies the essential context an agent needs.

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 schema already provides a complete description of the 'domain' parameter with an example (example.com), and the tool description adds no extra parameter semantics beyond what the schema offers. With 100% schema coverage, the baseline of 3 is appropriate.

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 the tool's function: 'Look up WHOIS information for a domain' and enumerates the key data returned (registrar, creation date, expiry date, nameservers, domain status). This specific verb+resource pairing distinguishes it from sibling tools like dns_lookup, ip_info, ssl_check, and http_ping.

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 implies usage context (when domain registration details are needed) but does not explicitly state when to use this tool versus alternatives, nor does it mention exclusions. The agent must infer from sibling tool names and the description's content, so guidance is only implicit.

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