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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful context beyond that: the base-currency XOF total is always returned regardless of the requested currency, and shipping fees are deliberately excluded (deferred to payment). It does not cover error cases such as an invalid or expired cart_id.

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 tight sentences with zero filler, front-loading what the tool returns before the currency behavior and the shipping exclusion. Every clause carries information.

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 must carry the return-value burden and does so reasonably (contents, subtotal, total, mandatory XOF total). Combined with annotations covering the safety profile and 100% schema coverage on inputs, the main remaining gap is error/edge-case behavior for an invalid or expired cart.

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 both cart_id and currency are already documented in the schema, including the enum list and the XOF-always-returned rule. The description restates the currency/XOF behavior but adds no new syntax or format detail, which is the expected baseline of 3 when the schema does the heavy lifting.

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 the resource (panier) and enumerates the returned data (contenu, sous-total, total, plus a mandatory XOF total), so an agent knows exactly what this read tool yields. It does not explicitly differentiate itself from siblings like add_to_cart or start_checkout, but the resource noun makes the distinction obvious in context.

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: 'Les frais de livraison sont calculés au paiement' hints that shipping costs belong to the checkout step, weakly routing the agent toward start_checkout rather than this tool. There is no explicit when-to-use statement, no prerequisites, and no named alternatives.

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