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

The readOnlyHint=true annotation already signals that this is a safe read operation. The description adds that it returns statuses, which is a minimal behavioral detail, but doesn't disclose pagination, ordering, which statuses exist, or whether the list is scoped to the authenticated company. No contradiction with the annotations is present.

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 clear sentence with no unnecessary words. It is not front-loaded with any extra filler, though it could have been slightly more informative without becoming verbose.

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?

The description is minimal. It fails to mention that companyId is required, what domain types are included (e.g., purchased vs custom domains), whether results are paginated, or how statuses are represented. Given the extremely sparse input schema and the lack of output schema guidance, an agent still has meaningful unknowns when invoking this tool.

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 describes companyId only as a 'UUID value wrapper', which is uninformative. The description implicitly ties the output to 'the company's domains,' but it does not explain that companyId identifies the company whose domains are listed. Between the weak schema description and vague tool description, an agent gets only partial semantic coverage.

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 'Lists the company's domains with their statuses' clearly identifies both the action (list) and the target object (company domains with statuses). This is sufficient for an agent to distinguish it from nearby tools. It doesn't explicitly enumerate the statuses, but the purpose is 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 no guidance about when to prefer this tool over sibling tools such as check_company_name_availability or domain purchase tools. It simply restates the function name. There is no hint about which domain-related question this tool should or shouldn't be used for.

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