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

Annotations declare readOnlyHint=true, so the safety profile is covered. The description adds that results include a 'rule-based' score, which signals the scoring is deterministic and not a predictive model—useful context. However, it doesn't disclose return scope (radius of 'nearby'), pagination, or what happens if neither parameter is supplied. With annotations covering safety, a 3 is appropriate.

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?

A single, efficient sentence that front-loads the core content. It could be slightly more front-loaded by leading with the primary use case, but it wastes no words.

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 read-only lookup with 100% schema coverage and no output schema, the description is minimally adequate. It omits the spatial scope of 'nearby', how the likelihood score should be interpreted, and whether results are paginated—details an agent might need to call it correctly or interpret output.

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%, so both parameters are fully documented in the schema, including the conditional requirement and the preference for property_id. The description adds nothing beyond the schema, so baseline 3 is correct.

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 (planning applications and decisions) and adds a distinctive element (rule-based approval-likelihood score). This clearly distinguishes it from siblings like get_flood_risk or get_area_market, though it doesn't explicitly name an alternative. The verb is implicit ('get' from the name) but the content is clear.

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?

No guidance on when to use this tool versus siblings, no prerequisites, and no mention of alternatives. An agent must infer usage from the description alone. The schema hints at postcode vs property_id preference but that's parameter-level, not tool-level guidance.

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