whois_lookup

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

With no annotations provided, the description carries full responsibility for behavioral disclosure. It lists the output content but does not explicitly state the operation is read-only, nor does it mention potential limitations like unsupported TLDs, rate limits, or data completeness. While 'Retrieve' implies a safe read, the absence of any caveats or side-effect disclosure leaves behavioral transparency below the level expected when annotations are absent.

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 two sentences long, with the primary purpose and data types listed first, followed by a brief use-case sentence. Every word earns its place; there is no redundancy or filler. The front-loading of the action and scope helps an agent quickly understand the tool's role.

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 tool is simple (single parameter, no output schema), and the description covers the essential details: what it returns and why it is useful. Missing are explicit error scenarios (e.g., invalid domain, unsupported TLD) and confirmation of read-only behavior, but given its simplicity, these are minor gaps. The list of returned data fields gives enough context for an agent to anticipate the response.

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 input schema already fully describes the parameter (e.g., 'example.com' with protocol/path exclusion), and schema coverage is 100%. The description does not add any extra meaning about the domain parameter—it only restates 'domain name' in the purpose, which does not enrich the schema's guidance. This aligns with the baseline of 3 for full schema coverage.

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 retrieves WHOIS registration data for a domain, naming the exact resource and action. It enumerates the specific data returned (registrar, dates, nameservers, contacts, DNSSEC, age), which sharply distinguishes it from siblings like dns_lookup, ssl_check, and domain_availability.

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 mentions it is 'useful for checking domain ownership and registration info,' which gives a concrete use case. However, it does not explicitly contrast with sibling tools or state when to prefer this over them (e.g., 'for DNS resolution use dns_lookup'). The guidance is implied but not explicit, so an agent might not always know the right tool to pick.

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