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

Beyond the readOnly and idempotent annotations, the description adds meaningful behavioral detail: the tax rates involved, the 40% dividend allowance, the deductible CSG, the 2026 social contribution rates by type, and the stateless nature of the computation. It does not contradict the annotations and gives useful context without overclaiming.

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 dense but efficient: the core comparison and decision outcome are front-loaded, followed by the relevant rates and statutory sources. Every clause carries information needed for a tax tool, though the source citations could arguably be moved to metadata without losing agent-facing value.

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 complex tax comparison with no output schema, the description provides the essential context: the regime options, the applicable rates, the legal bases, and the expected conclusion of which option is more favorable. It could more explicitly state the output shape or edge-case exclusions, but the information provided is sufficient 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?

Schema coverage is 100%, so the baseline is 3. The description adds value by explaining the tax logic that links parameters: PFU at 12.8% IR plus social contributions, the 40% dividend allowance, and how the option barème interacts with marginal IR and the taxable income. This enriches understanding of type_revenu and montant beyond the schema.

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 clear, specific task: compare capital income taxation under PFU flat tax versus the progressive barème option and identify the more favorable option. It is unambiguous about the resource and the output, and it is clearly distinct from sibling tax tools by its comparative scope.

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 makes the intended use case clear: it is for capital income where both PFU and the barème option apply. It does not explicitly name sibling alternatives or state exclusions, but the subject is narrow enough that the agent can infer when to select this tool.

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