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

Annotations cover the read-only/idempotent/open-world profile, and the description goes well beyond them: it names the data sources (DGFiP cadastre, Géoportail de l'Urbanisme), states what is deliberately never returned (owners, property sales), clarifies the zoning output is not a building-permit decision, and explains download-link behavior (file built on open, nothing saved).

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?

It is long, but front-loaded with the 'use this when' trigger and organized as purpose, then data sources, then scope limits and caveats. Nearly every clause carries a distinct constraint; a small amount of repetition around location-vs-user could be tightened.

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 open-data lookup with an output schema present, the description covers everything needed to call it correctly: inputs accepted, geographic scope, sources, output form (map with GeoJSON/KML), and the important negative constraints. Nothing material is missing.

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% and each parameter already carries a description, so the baseline is 3. The description adds real semantic guidance beyond the schema: pass the place as the user names it (place name, address, or coordinates) and repeatedly clarifies it is the queried place, not the user's own location.

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 verb and resource set ('which cadastral parcel ... is at an address or point', plus PLU/PLUi zoning) with concrete field-level detail (commune, section, number, cadastral area; zone label/type). It explicitly distinguishes itself from siblings by noting find_places is not needed and that links must never go to open_gis_file.

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 explicit trigger contexts (before buying land or a house, before a building project) and explicit exclusions/scoping: France only, never use the user's current location, never pass download links to open_gis_file, and it pre-empts the find_places step. Nothing about when to select this tool is left to inference.

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