Check a name across TLDs

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

Annotations already declare readOnly, idempotent, and open-world lookup, which covers the safety profile. The description's real contribution is the default TLD set, which is not encoded anywhere in the schema, but it says nothing about lookup latency, registry rate limits, or whether availability is live-checked vs cached.

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 sentences with zero filler: the action and its input shape come first, the default set second. Nothing is repeated from the schema beyond the minimal example format.

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?

An output schema exists, so the description needn't explain return values, and 100% schema coverage handles parameters. The only real gap is sibling disambiguation among check_domain, check_domains, and suggest_domains, which the description leaves to the reader.

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 coverage is 100%, so the baseline is 3, and the description earns a bump by documenting the default value of the optional `tlds` array (.com, .net, .org, .io, .ai, .dev, .app, .co), which the schema omits entirely. It does not restate the 'no dot' format, but the schema already handles that.

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?

States a specific verb and resource ('Checks one name ... across several TLDs and lists which are available'), and the 'without extension' clarification separates it from the single-domain sibling. It never names check_domain, check_domains, or suggest_domains, so the differentiation is implicit rather than explicit.

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 scenario is inferable: a bare name plus bulk TLD availability. But there is no explicit 'use this when... instead of check_domains' or 'for suggestions use suggest_domains', so the agent must infer routing from the name alone.

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