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

With no annotations, the description carries the full burden. 'PRO.' hints at a paid/subscriber tier and the schema's access_token corroborates it, but the description never says this is a read-only lookup, how the 'top below-median' ranking is computed, or what the response contains.

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?

Two tight fragments with no filler, and the scope/interpretation is front-loaded. The leading 'PRO.' is terse jargon but does convey a tier signal efficiently.

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 tool with no annotations and no output schema, the description should explain the return shape (bands per postcode? distribution? ranks?) and the safety profile. Instead it stops at a one-line purpose, leaving the agent without enough context to interpret results confidently.

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% — both district (outcode examples) and access_token are documented in the schema, so the description needn't compensate. It says nothing about the parameters, so the baseline of 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?

The description names the resource precisely — EPC bands at postcodes of a district — and adds the business meaning (low E–G bands flag refurb/value-add potential). It lacks an explicit verb and doesn't distinguish itself from the deal_scan/planning_nearby siblings, so it falls short of a 5.

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?

There is no statement of when to use this tool, when not to, or how it relates to deal_scan, deal_scan_full, or planning_nearby. The refurb-potential framing hints at a use case, but that is an interpretation of output rather than invocation guidance.

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