ons_geo_area_summary

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

The annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds useful context about data provenance, mentioning cached ONS geographies, compact inventory counts, and curated NOMIS follow-up datasets. However, it does not disclose fallback behavior such as exact vs best_fit resolution, error cases, or why a lookup might fail, though the annotation coverage softens this gap.

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?

The description is a single sentence with no filler and front-loads the tool's purpose. It is efficient, though dense and jargon-heavy; a short structured list or a second clarifying sentence could have made the same content more legible without being wasteful.

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?

Given the tool has 11 optional parameters, no required parameters, and zero schema-level parameter descriptions, the description is not complete enough for reliable invocation. It does not explain how inputs combine (e.g., postcode vs UPRN), which values targetLevel can take, what derivationMode exact vs best_fit means, or what happens when multiple identifiers are supplied. The presence of an output schema and annotations prevents a lower score, but significant operational context 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 description coverage is 0% across 11 parameters, so the description must compensate. It does connect some parameters at a high level: 'area code, postcode, or UPRN' maps to id, postcode, and uprn, while 'inventory counts' and 'NOMIS follow-up datasets' roughly map to includeInventory/inventoryResponseMode and includeProfileDatasets/profileCategories. But targetLevel, derivationMode, inventoryResponseMode semantics, profileCategories formats, and the boolean flags are left unexplained, leaving too much to inference.

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?

The description names a specific verb ('Resolve'), a concrete resource ('compact OA/LSOA/MSOA/parish/ward/profile summary'), and accepted lookup inputs ('area code, postcode, or UPRN'). It does not explicitly contrast itself with sibling tools like ons_geo_by_postcode or admin_lookup_area_geometry, but the 'compact inventory counts' and 'curated NOMIS follow-up datasets' give it a reasonably distinct identity.

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?

No when-to-use guidance is given. The description does not state when this tool should be preferred over alternatives such as ons_geo_by_postcode, ons_geo_by_uprn, or landis_natmap_area_summary, nor does it mention any exclusions or prerequisites. The intended context is only weakly implied by the phrase 'from an area code, postcode, or UPRN'.

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