Redeem one coupon

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

Annotations already declare a non-read-only, destructive, idempotent, open-world operation, so the safety profile is covered. The description does add useful context beyond that — no money is charged and payment should only be supplied after external confirmation — but it never addresses the risk side of a destructive redemption: whether it can be undone, what happens if the coupon is already redeemed or expired, or what errors surface.

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 tight sentences with the action front-loaded and sequencing second; little waste. 'As a commercial operation' is the only phrase that adds vagueness rather than information.

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 destructive, multi-parameter write with no output schema, the description is adequate on the input side but silent on outcomes — an agent cannot tell what a successful redemption returns (applied discount, final total, operation id) or how failures are reported. The payment-must-equal-total constraint is only in the schema, not reinforced operationally.

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?

With only 17% schema description coverage across 6 parameters and nested objects, the description has to carry weight, and it does clarify that cart_id, context.user.id, and quote_id are alternative correlation keys — a choice the schema does not explain. However, order_id and the required context.cart contents get no mention, and the payment-vs-context.payment_method relationship is left implicit.

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 gives a specific verb and resource ('Confirm one coupon as a commercial operation'), and 'one coupon' implicitly separates it from the sibling redeem_multiple_coupons. It is clear enough to distinguish from quoting and issuance tools, though the word 'confirm' is slightly softer than the actual redemption semantics implied by the destructive annotation.

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?

It states sequencing explicitly: normally call after quote_single_coupon and reuse the same cart/context, and include payment only after external confirmation. It stops short of saying when NOT to use it (e.g., bulk redemption, which routes to redeem_multiple_coupons) or how it relates to record_operation_payment and reverse_operation.

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