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

readOnlyHint=true already establishes the safety profile, so the description's job is to add context — and it does, notably by disclosing that the payload includes data freshness/recency and a nested program block. It does not cover failure behavior for an invalid lot_id or any access constraints, which keeps it from a 5.

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, zero filler: the first front-loads the full return contract as a compact enumeration, the second gives the usage trigger. Nothing is redundant.

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?

With no output schema, the description carries the burden of describing return contents and does so thoroughly, including nested program data. Only the error case for a non-existent lot_id is left unspecified.

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 the schema itself explains that lot_id is the `id` returned by search_lots, so semantics are already fully documented. The description adds no additional meaning about the parameter, which is the expected baseline when the schema does the work.

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 ('Renvoie la fiche complète d'un lot') and enumerates the exact contents returned, so an agent knows precisely what comes back. It implicitly separates itself from search_lots (list) and compare_lots (comparison), but the overlap with get_program — since program details are included here — is not addressed.

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 a concrete trigger condition: use when the buyer wants to 'see the detail' of a dwelling. It provides clear contextual guidance but no exclusions or explicit alternatives (e.g. when to prefer get_program or compare_lots instead).

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