whois_lookup_by_domain

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

With no annotations provided, the description carries full burden for behavioral disclosure. It mentions pagination ('page number for paginated results') and source filtering, but lacks critical details like rate limits, authentication requirements, error handling, or whether this is a read-only operation. The description is insufficient for a tool with 3 parameters and no annotation coverage.

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 well-structured with clear sections (Args, Returns) and uses bullet-like formatting. It's appropriately sized at 5 sentences, with the purpose stated upfront. Minor improvements could include more front-loading of key information, but overall it's efficient with minimal waste.

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 3 parameters with 0% schema coverage and no annotations, but with an output schema present, the description is moderately complete. It covers the basic purpose and parameters, but lacks behavioral context (rate limits, auth, errors) and usage guidance. The output schema reduces the need to describe return values, but more operational details would be beneficial for this lookup tool.

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 0%, so the description must compensate. It lists all 3 parameters with brief explanations: 'domain: Domain name to lookup', 'page: Page number for paginated results', and 'source: Filter by WHOIS source (arin, ripe, afrinic, apnic, lacnic)'. This adds meaningful context beyond the bare schema, but doesn't provide format examples, constraints, or default behaviors for optional parameters.

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 performs a 'WHOIS lookup by organization domain' and returns 'WHOIS records for the domain', specifying both the action (lookup) and resource (WHOIS records). It distinguishes from siblings like 'whois_lookup_by_asn' and 'whois_lookup_by_ip' by specifying the domain-based lookup, though it doesn't explicitly contrast with all siblings.

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 no guidance on when to use this tool versus alternatives. It doesn't mention sibling tools like 'whois_lookup_by_ip' or 'get_ip_info', nor does it specify use cases, prerequisites, or exclusions for domain-based WHOIS lookups.

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