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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint=false, so the safety profile is covered. The description still adds real behavioral context beyond them: the fixed 24-month observation window, the aggregation level, and the fact that results include top companies and buyers alongside the headline metrics.

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 sentence, front-loaded with the core metric before the scope and the returned entities. It is dense but every clause carries information; a slight trim of the trailing 'avec les entreprises et acheteurs principaux' phrasing would make it tighter.

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 no output schema, the description carries the return-value burden and does so by enumerating the metrics (single-offer share, median offer count) and the accompanying entity lists. Combined with annotations covering the safety profile, an agent has everything needed to call it correctly.

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 already documents that an empty value means all of France. The description's 'France ou un département' merely restates the schema's contract, so the baseline of 3 applies for a fully documented parameter set.

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 measurement (single-bidder share and median bid count for public contracts) with a defined aggregation window and geographic scope, which is far more precise than the title alone. It does not, however, distinguish itself from the sibling qui_remporte_les_marches, which sounds like an adjacent view of the same data.

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: the phrase 'pour la France ou un département' hints that the tool is used for geographic comparison of competition intensity, but there is no explicit when-to-use statement and no mention of when another sibling tool would be the better choice.

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