Check domain availability

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

The description adds useful behavioral context beyond the annotations by explaining that the tool queries registries, which supports openWorldHint and clarifies why it works for external names. It does not contradict the readOnlyHint or destructiveHint, and the output schema covers return structure.

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 two sentences with no wasted words. The core purpose is front-loaded, and the second sentence efficiently explains scope and directs to the relevant sibling tool.

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 a single parameter, a full output schema, and safety annotations already present, the description provides all necessary context. It covers scope, behavior, and the key alternative, leaving no important gap for an agent to invoke the tool correctly.

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 input schema already provides complete parameter documentation with a clear example and explanation of 'fully qualified names'. The tool description itself does not add parameter semantics, so the high schema coverage keeps this at the baseline score.

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 specific action: checking whether domain names are available to register and returning availability for each. It also distinguishes itself from eurodns_domain_get by noting that registered account domains should be handled there, making the purpose and scope unambiguous.

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 provides explicit guidance on when to use this tool by stating it queries registries and works for any name, whether registered here or not. It also names eurodns_domain_get as the alternative for domains already in the account, giving clear routing advice.

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