whoisxml_whoisCurrent WHOIS for — registrar, creation/expiry dates, registrant org, name servers, and status. Example: whoisxml_whois({ domain: "google.com", _apiKey: "your-key" })
| Name | Required | Description | Default |
|---|---|---|---|
| domain | Yes | Domain name to look up, e.g. "google.com" (no protocol) | |
| _apiKey | Yes | WhoisXML API key (get one at whoisxmlapi.com — one key works across all products) |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false. The description is consistent with these and adds no behavioral quirks beyond listing output fields. With annotations covering the safety profile, the description provides minimal additional behavioral context, so 3 is appropriate.
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 a single sentence plus an example, front-loading the purpose with 'Current WHOIS for <domain>'. The example is somewhat redundant with schema examples but not harmful. It is compact and well-structured, with no wasted words.
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?
No output schema exists, so the description carries the burden of explaining return values. It lists the key fields (registrar, creation/expiry dates, registrant org, name servers, status), which covers what an agent needs to know about the output. It does not detail exact structure, error handling, or rate limits, but for a simple read-only lookup with annotations, this is adequate.
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?
Input schema has 100% description coverage with examples for both parameters. The description's example duplicates the schema's example and adds no new semantic meaning to 'domain' or '_apiKey'. Under high schema coverage, 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?
The description states 'Current WHOIS for <domain>' with a specific verb and resource, and enumerates the data returned (registrar, dates, registrant org, name servers, status). It does not explicitly differentiate from sibling tools, but the word 'Current' and sibling names like whoisxml_whois_history make the distinction inferable.
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?
No explicit guidance on when to use this tool versus alternatives. It does not mention whoisxml_whois_history for historical lookups, whoisxml_reverse_whois, or whoisxml_dns, nor does it provide any conditions or exclusions. The implication of 'Current' is weak and leaves selection to inference.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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