check_domain

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

Annotations already provide readOnly/idempotent/non-destructive hints, so the bar is lower; the description adds domain-specific transparency: it is a read-only lookup that does not register, transfer, or change DNS, and it explicitly warns there is no composite appraisal score—only flags and per-section detail. This sets output expectations beyond the structured annotations.

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?

Three sentences are used efficiently: the first front-loads what the tool is and what it returns, the second gives the use case, and the third handles exclusions and caveats. There is no filler or repetition of schema content.

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 no output schema, the description carries the burden of describing the response shape, and it does so by listing the report sections and clarifying that output is flags and per-section detail only. It also covers input scope, safety, and sibling routing, making it complete for an agent to invoke 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 schema already covers the single domain parameter at 100% with an example. The description adds meaning by framing it as 'one known domain' and 'a specific name,' signaling that the value must be an exact existing domain rather than a pattern or search term.

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 opens with a specific verb-object pair—'Due-diligence report for one known domain'—and enumerates the concrete report sections (RDAP, backlinks, authority, toxic-linker flags, Wayback, trademark links). It also explicitly distinguishes itself from siblings by stating it is not for generating names or listing pattern matches.

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 states exactly when to use it ('before buying a specific name') and gives explicit negative conditions with named alternatives: do not use to generate names (find_available_domains) or list pattern matches (find_available_domains_by_pattern). This leaves no ambiguity about routing.

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