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

The description adds substantial behavioral context beyond the readOnlyHint/idempotentHint annotations: it reveals that each result includes the price survey date, that 'assembly_estimated = true' means a Chaletiste estimate rather than a manufacturer figure, and that the urbanisme field uses codes (aucune, dp, pc). It also states that models missing the filtered data are excluded, which is a non-obvious behavior an agent must know before trusting result completeness. This goes well beyond what the annotations convey.

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?

Six dense sentences cover scope, filters, result shape, usage examples, exclusion behavior, and citation duty, with no filler. The first sentence quickly fixes the catalog size and categories, and each subsequent sentence adds a distinct operational fact. The length is proportionate to the tool's real complexity.

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?

Given 13 optional parameters, an exhaustive input schema, and no output schema, the description carries the full burden of explaining return value semantics and does so completely: result fields, interpretation of special flags, urbanisme codes, and the exclusion rule. It also provides the follow-up tool guidance and citation requirement. The only minor omission is an explicit contrast with the generic 'search' sibling, which is not material for correct invocation.

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 input schema already documents all 13 parameters at 100% coverage, so the baseline is 3. The description adds interpretive domain knowledge not fully present in the schema, such as wall-thickness meaning (28 mm storage, 44 mm three-season, 70+ habitable), the 20 m² permit threshold, and the meaning of dp/pc. It does not restate every parameter, but it enriches the most ambiguous ones.

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 concrete scope: searching among 'les 293 chalets en bois en kit' sold in France, with an explicit list of covered categories. It also names the downstream tools that consume the returned id (get_chalet, compare_chalets, estimate_total_budget, request_quote), which differentiates this search tool from siblings that act on an already-selected chalet. The first sentence alone makes the tool's purpose unmistakable.

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 example queries that should route to this tool ('quel chalet de 20 m² à moins de 6 000 €', 'abri livré en moins de 3 semaines', 'chalet habitable en 70 mm'), telling an agent exactly when to invoke it. It also hints at the follow-up workflow by stating that the returned id should be passed to get_chalet, compare_chalets, estimate_total_budget, or request_quote. However, it does not explicitly state when NOT to use it or contrast it with the generic 'search' sibling, so it does not fully earn a 5.

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