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

Annotations already establish read-only, idempotent, non-destructive, and closed-world behavior, so the description only needs to add context. It does so by describing returned history fields, candidate-list behavior for ambiguous names, and the fact that contact details are excluded. It does not discuss errors or rate limits, but those are less critical here.

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 front-loaded with the core resource and remains information-dense without obvious filler. It is somewhat long and run-on due to field enumeration and multiple clauses, but nearly every sentence carries useful selection or return-value context.

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 and read-only annotations, the description carries the burden of explaining return content, and it does: it lists the history fields, explains ambiguous-name candidate output, and notes the contact-detail exclusion. It is complete enough for an agent to call the tool 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%, so the baseline is 3. The description adds some lookup semantics beyond the schema, especially that the id comes from chercher_clients and that multiple name matches produce a candidate list, but it does not explain mois, inclure_offerts, or historique_limite beyond what the schema already says.

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 specific verb and resource: the history of ONE client, then enumerates the exact data returned (registration date, wallet, visit counts/rhythm, current card, rewards, recent visits). It clearly distinguishes this from the sibling search tool by noting that the identifier comes from chercher_clients and that ambiguous names return candidates.

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 gives explicit when-to-use examples such as “quand est venue Zoé pour la dernière fois ?” and “combien de fois Louis est-il venu ?”, explains lookup by id or first name/initial, and covers the ambiguity case by returning candidate clients. It also states a useful exclusion: no e-mail or phone is provided.

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