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

Annotations already mark this as read-only and idempotent. The description adds useful behavioral context: it is a paid tool, returns results sorted by distance, depends on coordinates from realty_complex_report, and only supports coordinate search for subway, hospital, and school. It does not detail the full response structure, but it does say it returns a facility list with distances.

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 compact and front-loaded: the main behavior appears first, followed by source-coordinate context, use-case framing, and alternative routing. Every sentence serves a purpose, with no filler or unnecessary repetition beyond the paid marker.

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?

There is no output schema, but the description compensates by explaining the return shape as a facility list with distances, noting the paid nature, providing coordinate provenance, and routing to alternatives. It is sufficient for an agent to select and invoke the tool correctly, though a precise response-structure note would make it fully complete.

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 100%, and the schema itself already explains latitude source, poi_type allowed values, combination syntax, and radius bounds/defaults. The tool description does not add much parameter-level meaning beyond the schema, so the baseline of 3 is appropriate.

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 action: retrieve surrounding location factors such as subway, school, hospital, and mart around given coordinates, sorted by distance. It also distinguishes itself from siblings like realty_location_scores and realty_poi_stats by clarifying it returns a facility list, not aggregate scores or regional statistics.

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 gives explicit when-to-use guidance: use this tool when a facility list with distances is needed, and use the free realty_location_scores location_facts instead when only nearest-station distance or count-in-radius is required. It also points out that mart/pharmacy data belongs to realty_poi_stats, and that coordinates should come from realty_complex_report.

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