whois-lookup

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

No annotations are provided, so the description carries the behavioral burden. It states the operation is 'passive' reconnaissance via 'public APIs', which conveys a read-only, non-intrusive behavior. It lists the returned information categories, giving the agent a clear expectation of the outcome.

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 short sentences with no filler. The core action and target are front-loaded, and the return summary is specific without being bloated.

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 has a single required parameter, no output schema, and no dependencies or prerequisites mentioned. The description enumerates the expected return items, which is sufficient for an agent to decide to call it, though it could note error cases or rate-limit behavior.

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 schema includes 100% parameter documentation with a clear example ('example.com'). The description adds little beyond restating that a domain is the target, but the schema already fully covers the single parameter's semantics.

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 uses a specific verb ('Perform') and resource ('WHOIS and passive DNS reconnaissance on a domain'), then lists the concrete output types returned. This clearly differentiates it from the sibling tools, which target hashes, CVEs, headers, payloads, passwords, and reports.

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?

It clearly implies this tool is for domain-focused recon and passively gathering registration/DNS data. It does not explicitly state when not to use it, but none of the sibling tools overlap with domain reconnaissance, so the intended use is unambiguous.

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