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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds real behavioral value by explaining what content the tool returns (per-energy source guidance) and why it matters, though it says nothing about output format or length, which is acceptable given an output schema exists.

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 purpose is front-loaded and every sentence carries information, but the full French/English duplication makes it longer than necessary for a one-paragraph guide. No filler or tautology, just some redundancy from bilingual restatement.

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 read-only guidance tool with a single optional enum parameter, an output schema, and annotations covering the safety profile, the description supplies everything needed: what it explains, when to invoke it, and its role in the heat-pump workflow. Return-value details are correctly delegated to the output schema.

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% and the single enum parameter is fully documented, so the baseline is 3. The description mentions the three energy sources implicitly (gaz, fioul, électricité), which loosely mirrors the enum, but adds no syntax or defaulting guidance 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 names a specific resource and action — a step-by-step guide to obtaining one's consumption statement — and explicitly scopes it to GRDF gas, Enedis/Linky electricity, and fuel-oil invoices. It also distinguishes itself from the sibling estimer_puissance_pac by naming that tool as the downstream consumer, so an agent can tell the two apart without opening schemas.

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?

It states the trigger conditions explicitly: use when the person does not have their statement, does not know where to find it, or asks how to download it. It also names the purpose in the workflow (input needed for heat-pump sizing), giving clear when-to-use context and a routing hint to the sibling.

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