check_domain

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

With no annotations, the description must fully disclose behavior. It mentions RDAP and WHOIS methods and TLD coverage, but fails to describe the response format (e.g., boolean, details), error handling, rate limits, or caching. This leaves the agent unsure of what to expect from the output.

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 concise with two sentences: one stating the core purpose, the second detailing supported TLDs. No redundant information, but could be slightly more structured (e.g., listing example TLDs or output hint).

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?

Given the tool has one parameter and no output schema, the description should cover return value and behavior. It defines input and scope but omits output details (e.g., returns true/false or availability object). This is a notable gap for an AI agent to correctly use the results.

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 has 0% description coverage for the single parameter 'domain'. The description adds context that it is a domain name for availability check, but does not specify format requirements (e.g., include TLD, no protocol, case sensitivity, IDN support). For a simple string, the added value is moderate, but more explicit guidance would be beneficial.

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 clearly states the tool checks domain availability for registration, specifying verb ('check') and resource ('domain name'). It mentions support for many TLDs, but does not explicitly differentiate from the sibling tool 'check_domains' (which likely checks multiple domains). The name and single parameter imply a single domain, but explicit comparison would improve clarity.

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 guidance is provided on when to use this tool versus the sibling 'check_domains'. There are no prerequisites, limitations, or context for selecting this tool over alternatives. The description only lists supported TLDs without usage recommendations.

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