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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so safety is covered. The description adds meaningful context beyond that: the auth requirement (API key plus account) and the composition of the score (security, privacy, public record), which is what the agent gets back.

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 short, front-loaded sentences with no filler; the output semantics lead and the prerequisites follow. Slightly telegraphic ('Trust and Reputation.' as a header fragment), but nothing wasted.

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 return-value burden and does state what the score is and its range. Params and safety are covered by schema and annotations; the only real omission is how this differs from the sibling domain-rating 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?

Schema coverage is 100% with only two parameters, so the schema already documents 'domain' and 'company' fully. The description adds no format, syntax, or disambiguation guidance beyond the schema, which is the expected baseline when the schema does the work.

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 the resource (a domain) and the output ('A 0 to 100 score from security, privacy, and public record'), which is more specific than a bare 'check trust'. However, it never distinguishes itself from the closely named siblings check_domain_rating and check_effective_domain_rating, so an agent can't tell from the description which score tool to pick.

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 supplies prerequisites ('Requires an API key', 'Needs a free StartupHub.ai account') but no when-to-use guidance and no routing away from the near-identical sibling rating tools. It tells the agent how to be allowed to call it, not when to choose it.

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