add_checkout_lines

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

No annotations are provided, so the description carries the full burden. It discloses the replace behavior but omits side effects (e.g., whether lines are appended or added), error conditions, or authentication requirements. For a mutation tool, this is minimal.

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, front-loaded sentences with no extraneous information. Every word earns its place.

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 add tool, the description provides basic context. However, with no output schema, return values are unexplained. It does not differentiate from many sibling tools that also modify lines, and lacks guidance on when the checkout is ready for lines.

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%, with descriptions for all parameters. The description adds a hint about replace=true but no further semantics beyond the schema. Baseline of 3 is appropriate.

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 verb (add), resource (product lines), and context (active checkout). It effectively distinguishes this tool from sibling tools that deal with orders, shopping notes, or other checkout actions.

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 hints at usage with the replace flag but does not specify when to use this tool vs alternatives like update_product_list_item or clear_product_list. No exclusions or context about prerequisites (e.g., checkout must be active) are provided.

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