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

Annotations already cover readOnly, idempotent, openWorld, and non-destructive behavior. The description adds valuable context beyond annotations: data comes from public sources and, critically, no environment data is returned unless at least one section is set to true. 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?

Two sentences, with the purpose front-loaded and the key usage warning immediately after. Every sentence earns its place with no filler.

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 13-parameter tool with 100% schema coverage and rich annotations, the description covers the core purpose, the input constraint, and the critical all-false behavior. It does not describe the output shape, but no output schema exists and the invocation path is clear.

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?

The schema fully documents all 13 parameters, so the baseline is 3. The description adds meaning beyond the schema by instructing the agent to set only useful sections to true and by clarifying the empty-result behavior when none are set.

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 the action ('Retourne'), the resource ('l'environnement d'une parcelle cadastrale'), and the required IDU format. It is specific enough to separate environment data from basic parcel lookup, though it does not explicitly name a sibling tool as the alternative.

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?

It gives explicit operational guidance for the boolean sections ('Passer à true uniquement les sections utiles') and warns that an all-false call returns nothing. However, it does not say when to prefer this tool over siblings such as get_parcelle or search_parcelles.

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