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

Annotations already indicate this is a non-read-only, non-destructive operation. The description adds meaningful behavioral context beyond annotations: the cart is anonymous, prices are frozen at addition, nothing is committed, and totals are excluding VAT and shipping. This is valuable and not contradicted by the annotations.

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 compact and front-loaded: it states what the tool does, the key pricing/commitment caveats, and the essential prerequisite. Every sentence earns its place with no fluff or repetition.

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?

The input schema is exhaustive and the description covers the conceptual model well. The main gap is that there is no output schema and the description does not explicitly state what the created cart returns (e.g., cart id), which could matter for subsequent update_cart or get_cart calls.

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 input schema already documents all parameters thoroughly. The description reinforces the requirement for productId and sku, but does not add significant meaning beyond the schema's own parameter descriptions.

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 uses a specific verb ('Crée') and resource ('panier anonyme'), and clearly states it can include initial lines priced at addition with frozen prices. It also distinguishes a cart from an order, which prevents confusion with quote or order tools among the siblings.

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?

The description provides clear context: create a cart, optionally with lines, and each line requires productId and sku from search_products. It does not explicitly name alternatives like update_cart or quote_by_quantity, but it gives enough context for when creation is appropriate.

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