Estimate Market Value

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

The readOnlyHint annotation already indicates this is a read-only operation, and the description is consistent with that. It adds valuable behavioral context beyond the annotation: the estimate is based on DVF sales data, uses a communal median, and explicitly ignores floor level, condition, and DPE rating. This is exactly the kind of limitation disclosure an agent needs to set expectations correctly.

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 three sentences and every sentence earns its place: the first states the core purpose and data source, the second gives the practical use case, and the third covers input alternatives and a critical limitation. It is front-loaded with the main purpose and appropriately sized for the tool's 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?

For a tool with no output schema, the description communicates that the result is an estimated market value, based on a communal median, and warns about precision limits. It also explains the main financial context and input alternatives. It could be slightly more explicit about the output format or currency, but overall it is sufficiently complete for an agent to 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?

The input schema already covers all five parameters with 100% description coverage, so the baseline is 3. The description reinforces the key distinction between property_id and the commune/property_type/area_m2 group, but this is also reflected in the schema where fields are marked as ignored when property_id is provided. It does not add substantial new parameter meaning beyond what the schema already documents.

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 states a specific verb and resource: it estimates the market value (valeur vénale) of a dwelling using real sales from the commune's DVF data. It also clearly contrasts itself with an expertise by saying 'Ce n'est PAS une expertise', which helps distinguish it from more precise valuation methods. This is far more than a restatement of the tool name.

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 a clear use case: determining the amortizable base when a property was held before being rented out, and explains that the market value at that date, not the purchase price, matters. It also explains the two acceptable input modes: property_id or commune + property_type + area_m2. It does not explicitly name alternative sibling tools or state when not to use it, but the context is clear enough for an agent to decide.

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