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

Annotations already declare idempotentHint=true, destructiveHint=false, and readOnlyHint=false, so safety is covered. The description adds real value beyond them by explaining the operational intent: this links a charge to the merchant's reference so a later refund is possible, which tells the agent the write is a bookkeeping association, not a fund movement.

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; the primary action and its purpose come first, followed by a compact parameter clarification. Nothing is padding.

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 and a trivial two-parameter input, the description covers purpose, timing, and one parameter. The unexplained charge_id and the absence of any note on what happens if the same order is recorded twice (beyond the idempotent annotation) leave a visible gap.

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 0%, so the description must compensate, and it does explain order_ref well (merchant payment id, e.g. Stripe PaymentIntent). But charge_id, the other required parameter, is never explained, leaving half the inputs opaque.

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 action (record the merchant's order reference) and its trigger point (after checkout), which is enough to distinguish it from siblings like request_payment or cancel_subscription. It's clear but doesn't explicitly contrast with any sibling tool.

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 phrase 'after checkout' implies the timing/context for use, and the refund rationale hints at why it matters. However, there is no explicit statement of when not to use it or which alternative to pick if the order has not been paid.

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