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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds behavioral context beyond annotations: it compares evaluated offers against the regulated tariff and surfaces its assumptions. It stops short of describing estimation accuracy or error behavior, so not quite a 5.

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?

Two front-loaded clauses with no filler, and the routing information comes immediately after the purpose. The semicolon-joined structure is dense but each clause 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 an output schema present, return values need no explanation, and the description covers the routing decision and the estimation basis. The only minor gap is that it doesn't state default behavior when option is omitted, which the agent must infer.

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 80%, so the schema already documents postal_code, proportion_hc, puissance_kva and conso_annuelle_kwh, including the HP/HC conditionality. The description lists inputs but adds no format or constraint detail beyond what the schema provides, so the baseline 3 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?

Names a specific function (fast residential estimation) plus the exact inputs (kWh, kVA, postal code, option) and the outcome (offer comparison at the regulated tariff). It explicitly distinguishes itself from the sibling analyze_bill, so an agent can route without opening either schema.

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?

Gives an explicit when-to-use/when-not rule: use this when no bill has been extracted, and use analyze_bill when structured bill fields are available. The alternative and the selecting condition are both named.

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