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

Beyond the annotations, it discloses that the tool is UK only, costs 10 credits (10p), returns `not_available` with reasons for underivable blocks, and that the income-basis value capitalises RV at the district's commercial auction net yield with `not_available` where no yield was published. It also warns that RV is a rating measure at the antecedent valuation date, not passing rent — valuable behavioral context that annotations cannot provide.

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 and front-loaded, opening with the report identity and key inputs before detailing outputs and caveats. It is relatively long and packed into a single paragraph with nested parentheticals, so structure could be improved, but most content earns its place for a complex report tool.

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's complexity, the description is complete enough: it covers scope, geographic limitation, cost, keying requirements, output block behavior including `not_available` reasons, and an important interpretation caveat. An output schema exists, so it does not need to enumerate return fields.

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 0%, so the description must carry parameter meaning. It identifies the two lookup keys as UPRN and VOA UARN and emphasizes that the tool is keyed on a UPRN, not an address, with a concrete workflow via address_autocomplete and address_resolve. It does not specify that at least one key is required or explain how to obtain a UARN, but it adds substantial semantics 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 clearly states a specific resource and report scope: a commercial property report keyed by UPRN or VOA UARN, covering rateable value, rent/capital indexes, income-basis value, auction history, owner, and lease. It does not explicitly distinguish this report from sibling tools such as property_report, property_summary, commercial_market, or commercial_index_series, so it falls short of the top score.

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 operational guidance: UK only, keyed on UPRN rather than address, and instructs the agent to use address_autocomplete then address_resolve to obtain a UPRN. It does not explicitly say when to choose this tool over sibling report or market tools, but the prerequisite workflow and cost are well stated.

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