Whois Lookup

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

The annotations already indicate read-only, open-world, and non-destructive behavior. The description adds that it 'spends requests' (network usage) and is useful for ownership confirmation, but doesn't reveal additional traits like rate limits or failure modes. Slight extra context beyond annotations.

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: the first describes what the tool does, the second explains its practical use. Information is succinct, focused, and well-ordered, with no redundancy.

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 simple read-only lookup with a single parameter, the description provides enough context for an agent to understand the purpose and when to use it. It doesn't describe output format, but that's not necessary for a tool with no output schema and a clear function.

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 description mentions 'for a domain,' giving a strong hint that the 'target' parameter expects a domain name. However, it doesn't explicitly clarify whether IPs or URLs are accepted, and there is no schema-level description. The hint is useful but not fully unambiguous.

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's function: retrieving WHOIS registration data for a domain, listing specific fields (registrar, org, dates, nameservers). This is distinct from sibling tools like DNS resolution or subdomain enumeration.

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 provides a concrete use case: confirming asset ownership before spending requests, which guides the agent on when to invoke this tool. It doesn't explicitly mention when not to use it, but the guidance is actionable and relevant.

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