cart_add

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

Annotations are absent, so the description carries the full burden of behavioral disclosure. It states the core mutation, but does not explain whether repeated adds increment quantity or create duplicate line items, whether an existing cart or auth token is required, or what side effects occur. This is a meaningful transparency gap for a mutating tool.

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 a single, short sentence with no filler and the core action is front-loaded. It is appropriately terse for a simple tool, though it omits parameter and usage details that could be added without much bloat.

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 low-complexity tool with an output schema present, the description covers the basic action. However, it omits the relationship to sibling cart tools, does not state authentication requirements, and leaves parameter semantics entirely to the schema. It is adequate but not fully complete.

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 the description does not mention product_id or quantity at all. The input schema only provides field names and types, leaving the agent without guidance on how to resolve product_id or how quantity behaves. The description fails to compensate for the low coverage.

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 clear verb ('Добавить') and identifies the resource (a product added to the existing cart). The phrase 'already lies in the cart' signals additive semantics that help differentiate it from cart_set_quantity or cart_clear, though it stops short of explicitly naming those alternatives.

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 the tool is for adding to an existing cart, but it gives no explicit guidance on when to choose cart_add over cart_set_quantity or cart_clear. It also does not mention prerequisites such as authentication or an existing cart. Usage context is implied rather than stated.

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