Check a domain's real-time WHOIS data to determine its availability and current registration status.
Performs an authoritative real-time registry WHOIS lookup for availability and registration status.
| Name | Required | Description | Default |
|---|---|---|---|
| domain | Yes | The domain name to check (e.g. 'mabuiag.com', 'gulfprovince.com') |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It adds useful traits like 'authoritative', 'real-time', and 'registry' to signal a live network lookup, but it does not disclose output format, potential failure modes, or whether results may be redacted or limited by TLD. This is adequate but has clear gaps.
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 front-loaded sentence with no filler. Every word adds value, and the key action and outcome appear first.
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?
This is a low-complexity tool with one fully documented parameter and no output schema. The description adequately states the purpose and result ('availability and registration status'), which is enough for an agent to invoke it correctly. Minor omissions like output formatting or error behavior prevent a perfect score.
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 schema fully documents the single 'domain' parameter with examples, so schema coverage is 100%. The description does not add any parameter-specific meaning beyond the schema, so the baseline of 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 names a specific verb ('Performs'), a specific resource ('authoritative real-time registry WHOIS lookup'), and the outcome ('availability and registration status'). This clearly distinguishes it from sibling tools like appraise_domain and evaluate_outbound_potential, which are about valuation and outbound potential rather than raw lookup.
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 phrase 'for availability and registration status' gives a clear context for when this tool is appropriate. It does not explicitly name alternatives or exclusion conditions, but the intended use case is evident and distinguishable from the siblings.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.