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 genuine behavioral detail on top: it discloses what comes back (a quick answer plus the guide URL) and the exact behavior when the parameter is omitted. It still says nothing about coverage limits beyond the listed chains.

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?

A single front-loaded sentence that states purpose, the covered chains, the return payload, and the no-argument behavior. The inline chain list is long but functional, since it enumerates the accepted values; nothing is redundant.

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 one-optional-parameter, non-destructive read tool with no output schema, the description supplies enough to call it correctly: the accepted values, the optional parameter behavior, and the return payload. Only cross-tool routing against list_guides is missing.

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 store parameter is fully documented in the schema, including the 'vide = liste' semantics. The description echoes the optional/empty behavior but adds no format or matching guidance (e.g. accent/casing tolerance) 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 (a « sans gluten chez … » guide for a given supermarket chain) and the shape of the response (quick answer + guide URL). An agent can tell this is a store-specific gluten-free shopping guide. It does not, however, distinguish itself from the sibling list_guides, which appears closely related.

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: query a named retailer to get its gluten-free guide. The description explains the no-parameter fallback (lists all covered chains) but never says when to prefer this tool over list_guides or get_comparatif, so routing between siblings is left to inference.

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