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

With no annotations provided, the description carries the full burden and does well: it discloses the exact return format (fraction 0-1 and 'pourcentage' field), the applicable rates (17.2% vs 18.6%), and the legal sources. It does not cover edge-case behavior, but that is a minor gap for a simple lookup tool.

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 compact and well organized: the purpose comes first, followed by rates, return format, the distinction from tmi, and sources. There is no redundant 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 tool with one enum parameter and no output schema, the description tells an agent what input is needed, what output to expect (fraction and percentage), what units to use, and which legal references apply. The agent has enough information to select and invoke the tool correctly without further lookup.

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%, and the single parameter 'type_revenu' is already fully documented by the enum with legitimate values and an example. The description adds the contextual notion of 'revenu du capital' but does not need to restate parameter details the schema already handles.

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 tool's purpose: returning the French social contributions rate (taux de prélèvements sociaux) based on the nature of capital income. It names specific rate values, distinguishes this from the sibling 'fiscal_tmi' tool, and makes clear it returns a rate not tax points.

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 explicitly warns 'à distinguer de tmi' and explains that tmi returns percentage points (unit PERCENT, 0-100) while this tool returns a fraction (unit RATE) plus a percentage field. This gives an explicit routing decision: use this tool for PS rates and the other one for TMI points.

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