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

Beyond the readOnlyHint annotation, the description discloses important behavioral caveats: results are limited to snapshot coverage, provenance flags like older_records_exist and sample_complete must be checked, and an empty result only means no sales within coverage. These are non-obvious behaviors that materially affect interpretation, and they are clearly stated.

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 dense but every sentence earns its place: core function, filtering behavior, parameter semantics, and critical interpretive caveats are all covered. The use of bold labels and short paragraphs makes it scannable, and there is no filler or repetition.

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 output schema exists and carries return-shape details, the description covers all decision-relevant context: what the results mean, how to interpret empty results, when to use an alternative tool, and how to restrict results. An agent can correctly select, invoke, and interpret this tool without needing additional implicit knowledge.

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%, so the description fully carries the burden of explaining parameters. It explains limit as 'Returns up to limit most recent transactions,' defines postcode as the query key, and lists all property_type codes with their meanings (F=flat, D=detached, etc.). Every parameter is given functional meaning beyond the bare schema.

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 precise statement: 'Land Registry Price Paid transactions for a postcode, most recent first.' It names the data source, the specific query resource, and the ordering behavior, and it distinguishes this tool from property_comps by noting the alternative is for 'clean residential comparable sales.' 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?

The description explicitly says the tool is 'Unfiltered by default' and that category-B bulk transfers and commercial sales are included, telling the agent when filtering with property_type is appropriate. It also directs users to property_comps for 'clean residential comparable sales' and warns against treating empty results as 'never sold,' giving clear when-to-use and when-not-to-use guidance.

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