list_carts

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description correctly aligns as safe and non-destructive. It adds value by specifying returned fields (cart_uuid, store, items, timestamps) and the one-cart-per-store rule, though it does not mention potential pagination or filtering behavior.

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 sentences, no wasted words. The first sentence states the purpose and return format; the second provides critical usage guidance. Information is front-loaded and easy to parse.

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?

Given the simple list operation, strong annotations, and no output schema, the description covers core aspects: what it returns, when to use it, and the constraint. However, it could be slightly more explicit that this is user-scoped (implied) and that results are unsorted. Overall, complete enough for effective use.

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%, so the baseline is 3. The description does not add new meaning beyond what the schema provides; it references store and items in the return but does not elaborate on the 'intent' or 'store_id' parameters. Thus, it meets the baseline without improvement.

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 it lists the user's open (unsubmitted) carts and specifies the return fields (cart_uuid, store, items, timestamps). It distinguishes from siblings like show_cart or delete_cart by focusing on open carts and providing a pre-creation check use-case.

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?

Explicitly advises to always check this before creating a cart at a store, explains the constraint (only one open cart per store allowed), and instructs the agent to ask the user whether to extend or replace if one exists. This provides clear when-to-use and alternative handling guidance.

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