domains_whois

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

With no annotations, the description fully discloses cost ($0.005 per call), data source (authoritative registry's RDAP server), caching (up to 24 hours), and error behavior (unpaid 404 for unregistered domains). No contradictions.

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 front-loaded with cost and purpose, then lists data fields, use cases, and limitations. While informative, it is somewhat verbose and could be more concise without losing value.

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 the simple parameter structure, lack of output schema, and no annotations, the description covers input requirements, behavior, use cases, limitations, and caching. It is fully self-contained and complete for an agent to use 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?

The single parameter 'domain' is fully described in the input schema (pattern, description). The tool description adds an example ('example.com') but no additional semantic value beyond the schema. With 100% schema coverage, baseline 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 explicitly states it retrieves normalized WHOIS/RDAP data for a domain, listing specific data points (registration/expiry/update dates, registrar, EPP status codes, nameservers, DNSSEC) and TLD coverage (all gTLDs, most ccTLDs). This clearly differentiates it from sibling tools, none of which are domain-related.

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 enumerates specific use cases (domain availability checks, ownership research, expiry monitoring, security screening) and notes limitations (unregistered or RDAP-less domains return a 404). However, it does not differentiate from the sibling tool 'report_domain', which may serve a similar purpose.

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