cart_set_quantity

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

With no annotations, the description carries the burden of behavioral disclosure. It reveals two non-obvious behaviors: quantity=0 deletes the product, and for weighted goods the step is defined by basket_step in the product card. This goes beyond the tool name and schema.

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 concise sentences, front-loaded with the main purpose followed by important edge-case behavior. Every sentence earns its place with no filler.

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?

Given only two parameters, an output schema, and no annotations, the description covers the essential behavior: setting quantity, removing via zero, and weighted-item stepping. It could additionally mention auth or cart-existence requirements, but those are not critical for this straightforward mutation.

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%, so the description must compensate. It adds meaningful semantics for the quantity parameter, including the zero-removal behavior and weighted-goods step rule. product_id is left self-explanatory, but the description still adds value beyond the raw 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 states a specific verb ('Задать') and a specific resource ('количество товара в корзине'), clearly distinguishing this tool from cart_add, cart_clear, and cart_view. It is unambiguous about what the tool does.

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 gives clear context: use it to set the quantity of a cart item, and explicitly states that quantity=0 removes the item. It does not explicitly name alternatives or exclusions, but the usage context is sufficiently clear.

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