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

Annotations only indicate readOnlyHint and openWorldHint, so the description adds meaningful behavioral context: the entire basket is evaluated as a whole, and a split shipment is not allowed for eligibility. This clarifies important decision semantics beyond what annotations provide.

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?

The description is a single focused sentence that front-loads the core purpose ('Whole-basket Website Express verdict') and then adds the critical constraint. Every word earns its place, with no repetition of schema details.

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?

The core semantics are clear and the schema covers parameters fully, but there is no output schema and the description does not hint at the response format or what happens when the basket is ineligible. A brief note on the verdict's return shape would make it more complete.

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%, so the schema already documents items, id, quantity, and locale. The description adds little beyond naming 'product ids and quantities' and clarifying the basket-level semantics, which is already implied by the schema structure. Baseline 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 a specific resource (whole-basket Website Express eligibility) and operation (verdict), and the phrase 'every line must be eligible' distinguishes it from per-line or split-shipment tools like check_shipping_availability. The purpose is unambiguous and not a tautology of the tool name.

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 that this tool is for whole-basket express eligibility checks, but it does not explicitly say when to use it instead of alternatives such as check_shipping_availability, estimate_delivery, or get_express_delivery_status. No direct when-to-use or when-not-to-use guidance is provided.

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