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

Annotations already declare readOnlyHint=true, idempotentHint=true and openWorldHint=false, so the safety profile is covered. The description adds the useful fact that results follow the official fiscal barème, but says nothing about the comparison behaviour hinted at by 'autresFraisReels' and 'salairesNetsImposables', nor about the shape of the returned result.

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?

One tightly written sentence with no filler, and the calculation basis is front-loaded. It is arguably too terse for a six-parameter tool, but every word earns its place.

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 six parameters, 33% schema coverage, no output schema, and clear evidence of a comparison feature (frais réels vs abattement 10%), the description should explain what the tool returns and what 'electrique' does. It stops at naming the barème inputs, leaving the most consequential behaviour undocumented.

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 only 33%, so the description must carry weight; it does explain typeVehicule (voiture/moto/cyclomoteur), puissanceFiscale and distanceAnnuelle. It is silent on 'electrique' (a materially important option for the barème) and on how the two optional comparison parameters affect the output.

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 gives a specific verb ('Calcule') and resource ('indemnités kilométriques') and names the calculation basis (barème fiscal, vehicle type, fiscal horsepower, annual distance). No sibling tool covers mileage allowances, so confusion risk is low, but the description never explicitly distinguishes itself from the payroll/simulation siblings.

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?

Usage is only implied by the domain vocabulary; there is no statement of when to pick this calculator over a sibling such as salaire_brut_en_net, and no prerequisites or exclusions are given. An agent must infer the context from the name and required parameters alone.

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