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

Beyond annotations, the description discloses that this is an unsigned transaction builder, returns base64, never receives keypair bytes, and requires local finalization when signing is needed. This is especially valuable given destructiveHint=true, because it clarifies that the destructive cancellation is not executed by the hosted tool itself.

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 core action and return value are front-loaded in the first sentence, followed by a structured execution-guidance block. The guidance is useful, but it is partly boilerplate and repeats the 'unsigned transaction builder' intent, so it is not as tight as a 5.

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 100% schema coverage, annotations, and an output schema present, the description covers the purpose, return format, paid pricing flow, routing fallback, and signer boundary. An agent has all necessary context to invoke the tool correctly and understand the subsequent signing requirement.

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 all five parameters. The description adds no parameter-level meaning beyond what the schema provides, keeping this at the baseline of 3.

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 states a specific verb and resource: 'Build an unsigned cancel orders by ID transaction for Phoenix.' The qualifier 'by ID' distinguishes it from sibling sap_phoenix_build_cancel_all, and it also announces the return value, transactionBase64.

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 gives clear execution context: estimate cost first, pay/build, finalize unsigned transactions locally, and fall back to sap_payments_call_paid_tool if x402 is not natively supported. It does not explicitly enumerate alternatives for cancel-order building, but the 'by ID' qualifier and SAP routing guidance provide sufficient context.

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