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

Annotations already cover the safety profile (readOnly, non-destructive, open-world), but the description adds behavior they cannot express: results are capped at 6 fuzzy matches, the tool never returns zero matches (a genuinely surprising quirk that changes how an agent interprets output), and each request is billed $0.005.

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, front-loaded with purpose, then result semantics, then next-step routing and cost. No filler; each sentence supplies a distinct decision-relevant fact.

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 contract itself (up to 6 matches, category_id + name fields, never empty) plus cost and the downstream routing path. Nothing an agent needs to invoke it correctly is missing.

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 query param already documents max length and examples, so baseline is 3. The description adds real semantic value by disclosing that the query is matched fuzzily and that the returned category_id is the handoff key for other tools, which the schema does not say.

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+resource ('Search Trustpilot categories') and immediately scopes it with 'by keyword'. It also distinguishes itself from the sibling cluster by naming search_trustpilot_companies' downstream partners (trustpilot_category_companies / trustpilot_category_details), so an agent can place it in the workflow without opening another schema.

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?

Gives clear usage context: call it to obtain a category_id, then pass that id to the two named follow-up tools, and 'check the names fit' since matches are fuzzy. It does not state when NOT to use it (e.g. vs. search_trustpilot_companies for company lookups), so it falls short of full alternative routing.

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