View cart

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

No annotations are provided, so the description must carry the burden. 'View' implies a read-only operation and 'authenticated user' signals an auth requirement. It does not detail whether any side effects occur, but for a simple view operation that is likely unnecessary.

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?

A single, well-structured sentence. The verb and object are front-loaded, and every word adds meaning. There is no padding or repetition of the title.

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 zero-parameter, read-only tool, the description is nearly complete. It identifies the resource and the key output (subtotal). It could perhaps mention that the full cart contents are returned, but the phrasing 'view the cart' implies this. Given the simplicity, no major gaps exist.

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?

The tool has zero parameters, so the description needs to add no parameter-level meaning. The rule establishes a baseline of 4 when no parameters exist, and the description correctly focuses on behavior rather than params.

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 specific verb ('View'), names the resource ('authenticated user cart'), and adds a concrete detail ('current item subtotal'). This clearly distinguishes it from sibling tools like update_cart_item or add_to_cart, which modify the cart, and order-related tools.

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 context is clear: this tool is for viewing the current user's cart and subtotal. It does not explicitly state when not to use it or name alternative tools, but among siblings the intended use is unambiguous because no other tool reads the cart.

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