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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds useful context about data freshness ('actuels', 'date de vérification') and the specific contents returned, which helps an agent understand what to expect.

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 front-loaded sentence that names the exact resources and includes the key qualifiers ('officiels', 'actuels', 'plafonds', 'date de vérification'). There is no redundant or filler content.

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 zero-parameter, read-only lookup, the description is largely sufficient: it names the products, the kind of data, and the freshness marker. Since there is no output schema, slightly more detail about the exact returned structure could help, but it is not required 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 tool has zero parameters, and the input schema is fully self-explanatory (coverage 100%). The description does not need to explain parameter semantics, so the baseline of 4 applies.

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 clearly identifies the resource: current official rates for Livret A, LDDS, and LEP, with ceilings and a verification date. It is specific enough to be distinguished from sibling tools, though it uses a noun phrase rather than an explicit action verb like 'returns' or 'gets'.

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 implies use when current regulated savings rates are needed, but it does not state when to use this tool versus alternatives such as statut_produits or simuler_interets_composes. No explicit exclusions or alternative routing are provided.

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