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

Annotations already declare readOnlyHint=true, so the safe-read profile is covered. The description adds real behavioral context beyond that: abandoned carts are returned by default, filtering/sorting/expansion are supported, and it maps to the backend REST call GET /carts. It does not contradict the annotation. It stops short of rate limits or default page size, which the schema already handles.

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 core action and scope, followed by the endpoint mapping. Every clause carries information; there is no filler or repetition of the schema.

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?

There is no output schema, so the description ideally would hint at the return shape (array of carts, pagination envelope), which it omits. Given the annotations cover the safety profile and the schema fully documents all five parameters, the definition is otherwise complete for an agent to invoke it correctly.

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 100%: page, limit, sort, where, and expand are each documented with format and examples in the schema itself. The description only summarises them as 'filtering, sorting, and expansion', adding no syntax or constraint detail beyond the structured fields, so the baseline 3 applies.

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?

States a specific verb (List) and resource (shopping carts) and adds a meaningful scope qualifier: it includes abandoned carts, not just active ones. The resource is distinct from every sibling (products, orders, customers, invoices, etc.), so an agent can select it without ambiguity.

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 implies usage by naming capabilities (filtering, sorting, expansion) and the underlying GET /carts endpoint, so an agent can infer this is a paginated read. However, it gives no explicit when-to-use/when-not-to-use guidance, and does not distinguish itself from a generic sibling like swell_query that could also retrieve carts.

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