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

Annotations already establish that the tool is read-only and idempotent; the description adds meaningful behavior by stating that it returns the applied rule, the processing delay, and service-public.fr sources, and that it reminds users the local PLU can be stricter. 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?

Three sentences carry the purpose, decision factors, outputs, and an important caveat with no filler. The most important information is front-loaded and every sentence earns its place.

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?

Despite having no output schema, the description states what is returned (rule, delay, sources) and which inputs influence the result. It does not spell out the exact thresholds or fully formalize the output structure, but it is complete enough for an agent to select and invoke the tool correctly.

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%, but the description adds decision logic beyond the schema: it explains that surface means the larger of footprint and floor area and links extension/PLU/protected-sector flags to the formalité outcome. This goes beyond the baseline of merely documenting parameter names.

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 opens with a precise verb, 'Indique la formalité d'urbanisme exigée...', names the resource ('chalet ou abri') and enumerates the possible outcomes ('aucune, dp, pc'). This clearly distinguishes it from sibling tools like get_chalet or search_chalets.

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 intended use is implied from the purpose: it answers what urban planning formality is required for a chalet/shelter. However, it never explicitly states when to call it versus alternatives and gives no exclusion or when-not-to-use guidance, so it stays at the implied-usage level.

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