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

Annotations already declare read-only/idempotent/no open world, so the safety profile is covered. The description adds genuine behavioral context beyond that: data source and filter (HM Land Registry Price Paid, standard category A sales only), minimum-sample thresholds (10 sales per median, both for the premium), and the leasehold-share-of-sales caveat that resolves a likely misreading.

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 with the core purpose, then the metric list and caveats. It is dense and long for one sentence, but nearly every clause carries distinct information (thresholds, sales-vs-homes distinction, exclusions); only the parenthetical threshold restatement feels heavy.

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 an output schema present, return values need not be described. The description covers scope, source, filter, every metric definition, sample-size thresholds, and explicit non-uses, which is everything an agent needs to invoke and interpret this correctly.

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 single area_id parameter is fully documented with a pattern and example. The description only restates that the area is LSOA or MSOA; the borough exclusion is already in the schema, so the description adds little beyond the structured fields. Baseline 3 applies.

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 and resource and then enumerates exactly which metrics it returns (12-month sales, turnover, leasehold share of sales, new-build/resale median £/m2 over 36 months, new-build premium, £/m2 growth). The scope 'one LSOA or MSOA' plus 'aggregates only' distinguishes it from siblings like get_area_metric, get_home_prices and get_nearby_sales_summary.

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?

Scope is implied clearly (one area, aggregates only, Price Paid standard category A), and 'never a valuation, a listing or addresses' usefully fences off misuse. However, it never names an alternative tool or states a condition that would route the agent to get_area_metric or get_home_prices instead, so routing must be inferred.

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