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

Goes well beyond the readOnly/idempotent annotations: provenance (official nightly ODS extracts), keying by stable ODS code, explicit data exclusions (telephone numbers dropped, practitioner files never ingested), and the 5-row/20-call preview behaviour. This is exactly the kind of context annotations cannot carry.

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-loads what the register contains, then provenance, then filter/pricing mechanics — every clause carries information. The second and third sentences are dense run-ons, but nothing is redundant padding.

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?

No output schema and no annotation-level semantics, so the description correctly carries the dataset shape, exclusions, and auth/cost model. It falls short only on the remaining undocumented filter parameters and explicit pagination behaviour, which an agent would need to guess.

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?

With 18 parameters and 0% schema description coverage, the description must carry the burden. It maps many filters (q, name, status, ods_code, org_type, parent_code, postcode, dates, prescribing_setting) but leaves town, outward_code, health_geography, national_grouping, page and per_page unexplained, and does not disambiguate the open/close before-vs-after date axes.

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?

Names a concrete resource (the NHS ODS register for England) and enumerates exactly what entities and fields it covers, from ODS code to parent organisation. Its scope is unmistakable against siblings like query_uk_care_locations or query_uk_charities without opening any 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?

Explains how filters combine (AND), what q does (searches all text fields), credit cost per call, and the unauthenticated preview limit — all genuinely useful invocation context. It never names an alternative tool or states when not to use this one, so it stops short of a 5.

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