util_whois_lookup

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

No annotations are provided, so the description carries the full disclosure burden. It conveys read-only semantics via 'Look up' and specifies the returned fields, but it says nothing about failure modes (unregistered domains, WHOIS privacy redaction, network timeouts) or operational characteristics such as rate limits.

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?

Two sentences with zero filler. The action is front-loaded, and the second sentence's return-field enumeration is genuinely informative rather than redundant. Every clause earns its place.

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 one-parameter lookup with no output schema and no annotations, the description covers purpose and return values adequately. However, it lacks error-behavior context, domain-format guidance, and any differentiation from sibling inspection tools, leaving gaps an agent would have to resolve by trial.

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 description coverage is 100% ('Domain to lookup'), so the baseline is 3. The description reiterates that the domain is the lookup target but adds no format guidance (e.g., no protocol/scheme, punycode for IDNs, .com vs IDN TLDs) beyond what the schema already says.

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?

States a specific verb ('Look up'), resource ('WHOIS information for a domain'), and enumerates the expected return fields (registrar, creation date, expiry date, name servers, domain status). The operation is unmistakable, though it does not explicitly differentiate itself from sibling network-inspection tools like monitor_dns_lookup.

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?

No guidance on when to use this tool versus the many sibling inspection tools (monitor_dns_lookup, util_tech_detection, security_ssl_analyze), and no exclusions or named alternatives. The intended usage context is only implied by the stated purpose.

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