add_to_cart

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

No annotations exist, so the description carries the full burden. It does disclose the non-obvious accumulative semantics (rather than overwriting the line), which is genuinely valuable, but it says nothing about failure modes (out-of-stock, invalid offer/seller pairing), permissions, or whether a new line is created when the product is absent.

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 short clauses, front-loaded with the effect and followed by the sourcing hint; nothing is redundant. Slightly undermined by the garbled encoding ('unités', 'déjà ') which hurts machine readability.

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?

A cart-mutating tool with no annotations, no output schema, and 0% parameter coverage needs far more: what happens to an existing line, what errors surface, and what the three required IDs mean. The description leaves most of that for the agent to guess.

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 0% and none of the four parameters are documented in the schema. The description only clarifies `quantity` (additive, default implied by schema) and vaguely points at search_products for the IDs; it never explains the product_id/offer_id/seller_id triple or why all three are required.

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?

States a specific verb and resource ('Ajoute `quantity` unités') and adds the key qualifier that the quantity accumulates onto what is already in the cart, which separates it from update_cart_line. It does not explicitly name that sibling, so differentiation is only implied.

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?

Gives one concrete sourcing rule ('IDs issus de search_products'), which tells the agent where to get the three required IDs. There is no guidance on when to prefer add_many_to_cart or update_cart_line, nor any exclusions or preconditions.

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