Search Price Paid Transactions by Postcode

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false. The description adds valuable behavioral context beyond these: it returns a maximum of 10 transactions, lists the exact data fields, restricts to England and Wales, and explains automatic postcode extraction from addresses. This is useful operational detail not present in the annotations.

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?

Three sentences, front-loaded with the main action, followed by return details and key constraints. No filler or redundancy. Every sentence contributes meaningful guidance, making this highly concise and well-structured.

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 single-parameter tool with a provided output schema, the description is complete: it states the data source, coverage area, reliability guidance, and expected return fields/count. There's no ambiguity that would require additional narrative. The output schema covers structural details, so the description's brevity is appropriate.

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?

The single parameter 'address_or_postcode' is already described in the schema with the same guidance (postcode most reliable, full address accepted). The description adds a small extra detail about automatic postcode extraction, but with 100% schema coverage, the schema carries the semantic weight. Per the rubric, 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?

The description opens with a specific verb+resource: 'Search HM Land Registry Price Paid Index by postcode or address.' It clearly distinguishes this tool from sibling tools by focusing on property transaction data, and states the return content (price, date, address, property type, tenure). This leaves no ambiguity about what the tool does.

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?

It gives clear contextual guidance: covers England and Wales only, postcode is most reliable, full address accepted with automatic postcode extraction. It doesn't explicitly name alternatives or exclusion conditions, but the guidance is sufficient for choosing this tool for price paid lookups. Score 4 rather than 5 because there's no explicit 'when not to use' statement.

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