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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so safety is covered. The description adds genuine context beyond that: each movement is dated and sourced ('datées et sourcées') from the SCPI Select observatory, which tells the agent about data provenance and trustworthiness — especially valuable since there is no output schema.

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?

A single dense sentence that front-loads the verb and resource, then layers provenance and the optional filter. No redundant or filler wording; every clause contributes.

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?

The tool is simple (two optional parameters, no output schema) and annotations cover the safety profile, so the description is close to sufficient. The remaining gap is what a 'mouvement' contains — date, source, old/new price, variation magnitude — and how results are ordered, which the description leaves 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 description coverage is 100%, so both parameters are already documented, giving a baseline of 3. The description reinforces that the SCPI filter is optional but adds no meaning about 'limite' (default 20, max 100) beyond what the schema already says.

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: lists upward and downward unit-price movements ('hausses et baisses de prix de part') from a named observatory. That is clearly distinct from sibling tools like fiche_scpi or comparer_scpi, although the description never explicitly names a sibling to contrast with.

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?

'éventuellement pour une seule SCPI' implies the optional filtering scenario, so the agent can infer when to pass the scpi parameter. However, there is no explicit guidance on when to prefer this tool over fiche_scpi or comparer_scpi for price information, and no stated preconditions.

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