whois_lookup

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

With no annotations, the description carries the full burden and does so: passive/non-contacting behavior, registry rate-limiting, frequent redaction by privacy services, exact cost (1 quota unit), and latency (1-5 seconds). This is the behavioral context an agent needs before spending quota.

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?

Four short clauses, front-loaded with what the tool returns, then passivity, then limitations, then cost/latency. Every sentence earns its place with no filler.

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?

An output schema exists, so return structure need not be explained. Combined with cost, latency, passivity, and redaction caveats, the description gives everything needed to decide and call correctly.

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?

Only one parameter and the schema already documents it at 100% coverage ('Domain name in scope.'). The description repeats the scope qualifier but adds no syntax, format, or normalization guidance, so the baseline of 3 applies.

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 resource (registration data) and source (registry's WHOIS server), which separates it from dns_lookup and certificate_transparency by data type. It stops short of naming an alternative explicitly, but the phrase 'registry's WHOIS server' pins the purpose well enough for selection.

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 'domain in scope' constraint implies when it is legal to call, but there is no explicit when-to-use versus alternatives like dns_lookup or certificate_transparency, and no stated preconditions beyond scope. An agent must infer from the data-source phrase alone.

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