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

Annotations already declare this a safe, read-only, idempotent, non-open-world operation, so the safety profile is fully covered and the description is not required to restate it. The description adds the useful temporal constraint ('latest month'), but says nothing about data recency, revision behavior, or how areas are matched, which the annotations do not supply.

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?

A single sentence that front-loads the scope marker 'UNITED KINGDOM' and then enumerates the returned metrics and geography levels. Dense but every clause carries information; the long list of metrics is the only mild bloat.

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 correctly enumerates what the tool returns (average price, 12-month change, price by property type, first-time buyer price) and the geography granularity, which is the information an agent needs to decide if this answers the query. Only minor gaps remain, such as data vintage beyond 'latest month'.

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 schema already documents examples and the empty=UK default, so the baseline is 3. The description goes slightly beyond it by defining the valid area universe (a nation, an English region, or one of the 20 areas Payotte covers), which directly informs what strings the 'area' parameter will accept.

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 specific resource and scope: UK average home price plus 12-month change, property-type breakdown and first-time buyer price, for the UK, a nation, region or one of 20 covered areas. It also implicitly distinguishes itself from the many sibling price tools (house_prices_us/au/in) via the UK/US/UK-region scope, though it never names them.

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?

Usage is only implied: an agent can infer this is the tool for UK house price figures, but there is no explicit when-to-use, when-not-to-use, or pointer to alternatives such as compare_nations_uk or stats_marche. No caveats about which geography the user must supply are given beyond the schema.

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