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

Annotations already cover the safety profile (readOnly, non-destructive, idempotent). The description adds genuinely useful behavior: a 30-credit cost, a UK geographic constraint, the UPRN keying requirement, and caveats that flags are evidence not proof and backfilled floor areas are modelled. It does not explain output shape, but an output schema exists.

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 purpose is front-loaded, but the body is a dense block mixing operational facts (cost, geography, address flow) with lengthy domain methodology advice about flags, duplicate tuples, and demises. Some sentences earn their place; others are tangential to invocation.

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 handling return values and annotations covering safety, the description supplies the remaining essentials: cost, geography, the prerequisite address flow, and data-quality caveats. It is close to complete, missing only guidance on the max_backfills parameter.

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% for 2 parameters. The description clarifies that 'uprn' must be a UPRN (with a path to obtain it), which compensates somewhat for the required param. However, 'max_backfills' is never mentioned anywhere, leaving one of two parameters fully undocumented.

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 resource and scope: 'Comparable sales in the same building or block.' The agent knows this returns comps rather than a valuation. It does not explicitly distinguish itself from siblings like valuation_comparables or comps_adjustments, so it misses the top mark.

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?

Gives concrete routing guidance: it is keyed on a UPRN, not an address, and instructs to call address_autocomplete (free) then address_resolve. It also notes 'UK only' and 'Costs 30 credits.' It stops short of saying when to prefer this over sibling comps tools.

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