Add to cart

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

The description reveals the critical behavioral trait: the tool is read-only when confirm=false and mutating when confirm=true, going beyond the annotations which only indicate global readOnlyHint=false. It also addresses handling of products requiring option selection.

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 well-structured sentences cover the main action, the two-phase behavior, and an edge case. Every sentence is necessary and no redundant information.

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 tool with 3 parameters, no output schema, and partial annotations, the description covers core behavior and an important edge case (options). It could optionally describe the preview return format, but overall it is sufficiently complete for correct invocation.

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?

With only 33% schema coverage, the description adds meaning to url (the product to add), clarifies confirm's role (preview vs add), and explains quantity's default and max. The mention of 'default option' for products with options provides additional context not in the 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 clearly states the tool adds a product to the cart, with a two-step process using confirm flag. It distinguishes from sibling tools like get_cart, remove_from_cart, and proceed_to_checkout by focusing on adding and previewing.

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 explicitly explains when to use confirm=false (preview) and confirm=true (actual add). It doesn't explicitly mention alternatives like using get_cart after adding, but the context is clear enough for an AI agent.

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