add_to_cart

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

Beyond annotations (which show non-readOnly, non-idempotent, non-destructive), the description discloses key behaviors: no charge (cost impact) and invalidation of checkout preview (state change). This adds value, though auth requirements or side effects on other sessions are not mentioned.

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 sentences, front-loaded with the main action ('Add a product'), followed by critical behavioral notes. No wasted words.

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?

Covers purpose and key behavioral traits, but lacks parameter guidance and explicit usage differentiation from siblings. An output schema exists, so return value explanation is not needed, but the description still feels incomplete for a new user.

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%, but the description provides no explanation for either 'product_id' (required) or 'quantity' (optional). It does not clarify format, constraints, or meaning beyond what the schema already provides.

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?

Specifically states 'Add a product' which is a clear verb+resource combination. The tool name also reinforces this. Adds additional context about no charge and invalidating checkout preview, going beyond a simple tautology.

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?

Implies usage for adding products to cart, but does not explicitly differentiate from siblings like 'update_cart_item' for quantity changes or 'clear_cart' for removal. No guidance on when not to use or prerequisites.

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