whois_lookup

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

Beyond the annotations, the description adds valuable behavioral context: data is sourced live from IANA RDAP bootstrap with rdap.org fallback, and GDPR redaction of registrant data is normal rather than an error. It also explicitly states there is no auth and no side effects, reinforcing the read-only annotation.

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 information-dense but well-structured: it fronts the core function, then return data, data source, a key caveat, use cases, and an alternative tool. Every sentence earns its place and there is no superfluous content.

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 single-parameter tool with no output schema, the description is remarkably complete. It explains what is returned for both domains and IPs, notes live data sourcing and fallback behavior, clarifies a common confusion (GDPR redaction), and provides usage guidance and tool alternatives.

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 comprehensively documents the single parameter with 100% coverage, so the description adds little beyond restating that query is a domain name or IP address. Baseline of 3 applies because the schema carries the semantic load.

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 a read-only WHOIS/RDAP lookup tool for domains or IP addresses, specifying exactly what data is returned for each input type. It distinguishes itself from sibling tools by explicitly naming lookup_dns as the alternative for DNS records.

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 provides explicit use cases: check domain ownership, age, expiry, vet suspicious domains, or find an abuse contact. It also gives a direct exclusion: 'for DNS records use lookup_dns instead.'

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