whois_lookup

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

With no annotations, the description carries the behavioral burden. It discloses meaningful behavior: uses TCP port 43, auto-discovers the WHOIS server via IANA, follows thin-to-thick referrals, and returns both parsed and raw data. It does not cover error handling, rate limits, or network failure modes, but for a read-only public lookup tool this is strong transparency.

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 sentences, each earning its place: what it does, how servers are discovered, how referrals are handled, and what the return includes. Front-loaded with the core action and 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?

The description covers the tool's core operation, behavior, and return value shape, which matters because there is no output schema. Parameter semantics are already in the schema. It could be more complete by explicitly contrasting with rdap_lookup and whois_raw, but an agent has enough information to invoke this tool 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?

Schema description coverage is 100%, so all four parameters are already documented in the input schema. The description adds contextual value by mentioning IANA auto-discovery and referral following, but it does not need to re-explain parameter meanings. Baseline 3 is appropriate.

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 and resource: "Look up WHOIS information for a domain name using native WHOIS protocol." It clearly differentiates from siblings like rdap_lookup (different protocol) and whois_raw (raw-only output) by stating it returns "parsed structured data + raw WHOIS text" and follows referrals.

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 gives clear context: this is the native-WHOIS lookup tool with automatic server discovery and referral following. It implies use for complete WHOIS data, but it does not explicitly state when to choose rdap_lookup or whois_raw instead. It is clear enough for selection, but lacks explicit exclusions or alternative routing.

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