domains_check_domain_available

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds only the HTTP route and says nothing about cost, rate limits, whether this is a live registry query, or what the check returns — meaningful gaps for an open-world external lookup.

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?

Two short lines with zero filler and the purpose front-loaded. It is tight but also borders on under-specified, since nothing beyond the verb and route is included.

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 simple read-only check tool with no output schema, the description should at least say whether the response indicates available/taken or returns candidate zones. Combined with the absence of any sibling differentiation, an agent lacks the context needed to call this confidently over the adjacent check tools.

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?

Top-level schema coverage is 0%, so the description is the only place to explain the body parameter and it adds nothing. Nested properties (name, count, excludes, challenge) do carry their own schema descriptions, which limits the damage, but the description never clarifies how count/excludes influence the availability result or that name accepts a bare label versus a full domain.

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 a specific verb and resource ("Check domain availability") plus the underlying endpoint POST /domains/check, so the agent knows exactly what operation this is. It does not distinguish itself from closely named siblings such as domains_check_domain_delegation or domains_schedule_ns_check, which keeps it from a 5.

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?

There is no when-to-use guidance, no statement of when not to use it, and no reference to alternatives for related checks (delegation, nameserver checks, or actual domain creation). An agent must infer the routing decision purely from the tool name.

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