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

No annotations are present, so the description carries the disclosure burden. It clearly enumerates the returned fields, says it provides a summary, and notes it is a free tool, which suggests no authentication or payment barrier. It does not discuss redacted WHOIS data or rate limits, but these are minor for a read-only lookup.

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 compact sentences with the key payload front-loaded: registrar, dates, nameservers, DNSSEC, and status flags. The attribution clause is short and does not dilute the purpose.

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?

With one required parameter and no output schema, the description lists the expected return fields, which is enough for an agent to invoke and interpret results. It omits edge considerations like WHOIS redaction or availability guarantees, but those are secondary for a simple 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 coverage is 100% and the schema already documents the domain parameter with an example. The description only restates 'for a domain' and adds no additional syntax, format, or validation detail beyond the schema, so the 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 states the result precisely: a WHOIS summary with registrar, dates, nameservers, DNSSEC, and status flags. It is clearly about domain WHOIS data, but it does not explicitly contrast with the sibling get_domain_age, which likely overlaps on registration date.

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?

Usage is implied: an agent should call this when it needs a WHOIS summary for a domain. However, there is no explicit when-not-to-use guidance or mention of alternatives among the sibling tools, so routing is left to inference.

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