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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), yet the description still adds real behavioral detail: the exact Markdown return shape, the 'no evidence' placeholder for empty axes, and the unknown-slug fallback returning up to five near matches. The degradation path on bad input is the kind of thing an agent cannot infer from the schema.

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?

Front-loaded with purpose and return contents, then the failure mode. The second sentence is dense with comma-separated clauses but every clause conveys distinct information; minor padding in 'where a real one exists' and the trailing get_evidence sentence keeps it from a 5.

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?

Although there is no output schema, the description substitutes for it by specifying the Markdown structure, the table rows, the award line, and the URL. Combined with the input fallback behavior, an agent has everything needed to call and read the result.

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% and the single slug parameter is fully documented with format and an example, so the schema does the heavy lifting. The description only adds the behavioral consequence of a bad slug (near matches), which is useful but not parameter-level syntax guidance. Baseline 3 is appropriate.

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 ('Returns the RoomExpert verdict for one hotel') and enumerates exactly what the verdict contains: overall score, eight axis scores and their basis, coverage depth, loyalty program, award price. It is clearly distinguishable from siblings like search_hotels and get_evidence within one sentence.

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?

Frames the use case in the agent's own terms ('Answers "is this hotel any good" and "what is it strong at"') and routes the supporting detail to get_evidence. It does not explicitly state when to prefer search_hotels or get_rates instead, so it stops short of full when/when-not guidance.

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