update_quantity

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

Annotations already indicate destructive and idempotent behavior. The description adds that quantity 0 removes the product, which is important. However, it does not detail other behavioral aspects such as whether it overwrites existing quantity or any prerequisites, leaving some gaps.

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, efficient sentences front-load the verb and core behavior. No waste; every word adds value.

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 simple tool with two parameters and no output schema, the description covers the primary behavior (absolute set and removal) and is consistent with annotations. It does not address edge cases like invalid product ID, but that is acceptable given the tool's simplicity and the annotations.

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%, so the description adds meaning beyond the schema by clarifying that setting quantity to 0 removes the product. This supplements the property description of 'Nouvelle quantité absolue'.

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 clearly states the tool sets the absolute quantity of a cart product and specifies that a quantity of 0 removes it. This distinguishes it from siblings like add_to_cart (incremental) and remove_from_cart (unconditional removal).

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 implies use cases (set exact quantity or remove by setting 0) but does not explicitly state when not to use it or mention alternatives like add_to_cart for incremental changes. Sibling tools provide context, but the description itself lacks direct guidance.

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