check_domain

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

No annotations are provided, so the description carries the full burden. It states the core check behavior and supported TLDs, but does not disclose what the response looks like, whether any network lookup occurs, whether the check is real-time, or any edge cases like premium/restricted domains. This leaves important behavioral context undisclosed.

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 that front-loads the action and object, then immediately lists TLD constraints. No filler or repetition exists.

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?

For a single-parameter, no-annotation tool with no output schema, the description is minimally viable: it states the action, the input scope, and a key constraint. However, it does not explain the result format or semantics of 'unavailable', so agents cannot fully anticipate the tool's response.

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%, and the schema already documents the domain parameter with an example and supported TLDs. The tool description essentially repeats that limitation without adding new parameter-level meaning, so 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 uses a specific verb ('check') followed by a clear resource ('whether a domain is available for registration') and states the supported TLDs. This leaves no ambiguity about what the tool does, even without sibling context.

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 implies the tool is for domain availability checks but provides no guidance about when to use it versus alternatives, nor any exclusions or prerequisites. Since there are no siblings, the lack of explicit routing is acceptable but the guidance remains only implicit.

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