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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so safety is covered. The description adds genuine value beyond them: it discloses the required auth scope and, importantly, that cart tokens are omitted from results — a behavioral caveat an agent could not infer elsewhere.

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?

Three compact sentences, each carrying a distinct fact (definition, output caveat, auth/endpoint). It is front-loaded with the purpose and wastes nothing.

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?

With no output schema, the description usefully notes what is not returned (cart tokens) and how results are paged (in the schema). It is nearly complete for a simple read-only list tool, though it remains silent on result ordering and total counts.

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%, with page, limit, and since_id all documented in the schema, including pagination chaining via next_page. The description adds no parameter-level detail, so the baseline of 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 and resource ('List checkouts') and clarifies the ambiguous term with a parenthetical ('carts in progress or abandoned'). That disambiguates it from orders, but it doesn't explicitly differentiate from list siblings like list_orders in terms of what a checkout represents in the lifecycle.

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?

Gives prerequisite context ('Needs read_orders'), which helps an agent know when it can be called. However, there is no explicit when-to-use vs. when-not guidance or comparison to alternatives such as list_orders, leaving the usage decision implicit.

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