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

Beyond the readOnly/idempotent annotations, the description discloses real behavior: an in-flight seller payment is re-polled, no new payment is initiated, completed orders persist for 24 h unless they hold sats or a claim, and seller-supplied delivery text must be treated as data rather than instruction. The injection warning and retention rule are genuinely non-obvious. The "listed for 24 h" phrasing is ambiguous about where the listing occurs.

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 content is dense and mostly earns its place, but the opening is a fragment with no verb and the retention sentence ("listed for 24 h unless they hold sats or a claim") is too compressed to parse confidently. Telegraphic phrasing trades clarity for brevity in several spots.

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?

An output schema exists, so return shape needn't be explained; the description instead covers the side effect (payment re-check), the retention window, and the prompt-injection caveat, which are the things an agent could otherwise get wrong. The remaining gap is the missing explicit contrast with `orders`.

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 coverage is 100% and the single `order_id` parameter is documented in the schema as coming from a buy receipt or the orders list. The description adds nothing about the parameter, which is acceptable at full coverage but is the baseline rather than an improvement.

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?

"One order, including the stored result" identifies a single-record fetch and implicitly contrasts with the sibling list tool `orders`, and the follow-up sentences clarify that this is a read of existing state rather than a new payment. The verb is implied by the tool name rather than stated, and the sibling is never named, so an agent must infer the distinction.

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?

Usage context is implied rather than stated: retrieve one order by id, and note that an in-flight seller payment will be re-checked. There is no explicit "use this instead of `orders` when you have an order_id" routing, and no stated preconditions or failure modes, so the agent is left to infer when this beats the listing tool.

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