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

Goes well beyond annotations (readOnly/openWorld/idempotent) by disclosing data sources (Wikidata, Companies House, Open Government Licence), what the response contains (staff numbers, HQ, open job counts with examples, ready searches), and what is excluded (staff reviews). A small gap remains on freshness/caching or when UK records may be absent, but this is substantially rich for a read-only lookup.

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 well with the purpose and example queries, but the third sentence is a long run-on enumerating every returned field, which buries the most useful content. It sacrifices scannability for exhaustiveness.

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?

For a read-only lookup with no output schema, the description covers what is returned, the data sources and licences, exclusions (staff reviews), and US-visa augmentation. It is close to complete; a brief note on data recency or missing-company behavior would close the remaining gap.

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 description coverage is 100%, so the schema already documents both 'name' and 'where'. The description's mention of 'UK company records' and job scoping implies how the parameters behave but adds no format or example detail beyond the schema. 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 resource (employer facts + hiring) with concrete example queries ('tell me about Monzo as an employer', 'is Tesco hiring?'). Clearly distinguishable from siblings like get_job, search_jobs, or find_people, which operate on jobs or people rather than the company itself.

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 example queries imply usage context well, and the sentence 'Staff reviews are not included' rules out one alternative need. However, it never explicitly names alternatives (e.g., use find_people for people there, us_visa_salaries for deeper visa data), so routing to siblings is left to inference.

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