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

With destructiveHint=true and readOnlyHint=false already declared, the description still adds substantial value: it discloses the side effect (refund to wallet rather than card), the closed-loop nature, the rejection behavior when printing, and the 10-minute grace window. These are behavioral traits beyond what annotations convey.

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?

Front-loads the core effect (cancellation plus wallet credit) before drilling into the two modes, which is good structure. The bilingual duplication inflates length, but the German/English mirroring is functionally justified and each sentence carries 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 mutation tool with no output schema, the description covers the essential behavioral consequences, the two invocation modes, and the failure case, so an agent has enough to invoke it correctly. Minor gaps remain: no auth/permission note and no mention of the undocumented 'reasoning' field.

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 75%, just under the high-coverage baseline, and the description supplements it by clarifying that orderId and approvalId are alternative triggers with different semantics and windows. It does not mention the 'reasoning' parameter nor add format detail beyond the schema, keeping it short of 5.

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 (cancels a letter/order) and immediately discloses the financial outcome (amount credited to the wallet, closed loop). It also cleanly separates the two operational modes (orderId vs approvalId), so an agent can tell this apart from siblings like order_status or order_send without opening a schema.

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 clear conditions for each path: orderId cancels an existing order within the cancellation window, approvalId stops a chat-approved send inside its 10-minute grace window. It also states a when-not case (already printing is cleanly rejected). It lacks explicit routing to alternative sibling tools, so it stops short of a full 5.

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