reverse_geocode

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

Annotations already indicate safety (readOnlyHint=true, destructiveHint=false). The description adds behavioral details: uses IGN Géoplateforme, covers specific regions, and returns null for out-of-range coordinates. There is no contradiction with annotations.

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 concise, well-structured, and front-loaded. It conveys purpose, source, coverage, and edge-case behavior in two clear sentences without redundancy.

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?

The description covers the essential purpose, source, coverage, and null behavior. However, since there is no output schema, the description could mention the format of the returned address (e.g., string or structured object) to be 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% with basic descriptions for lon and lat. The description adds context about coordinates being in WGS84 but does not provide additional semantic meaning beyond what the schema already conveys. The null behavior is beneficial but not parameter-specific.

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 it performs reverse geocoding from GPS coordinates to find the nearest address, specifying the data source (IGN Géoplateforme) and geographical coverage. It effectively differentiates from sibling tools like geocode_adresse (forward geocoding) by focusing on the inverse operation.

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 explicitly mentions when to use the tool (reverse geocoding) and provides important usage context: coverage limited to metropolitan France and DOM, and that coordinates outside this area return null (not an error). However, it does not explicitly list alternative tools for other use cases.

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