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

The description adds meaningful behavioral context beyond annotations: it discloses that this is a hosted unsigned transaction builder, that a builder fee applies, that transactionBase64 is returned, and that value-moving results must be finalized locally when signing is required. It does not contradict the annotations and supplements the readOnlyHint=false and openWorldHint=true signals.

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 purpose is front-loaded in the first sentence, followed by structured, labeled guidance about intent, pricing, routing, and signer boundary. While the SAP MCP guidance is somewhat boilerplate and repeated in the schema description, it is organized and each section carries useful information without excessive 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?

For a paid hosted transaction builder, the description covers the essential workflow: estimate first, pay/build, receive transactionBase64, and finalize locally. It also provides routing fallback and signer-boundary constraints. With an output schema present and complete parameter descriptions in the schema, this is sufficiently complete for an agent to call the tool correctly.

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 every parameter. The tool description does not add additional meaning about parameters beyond what the schema provides. Per baseline rule, this warrants a 3 since the schema does the necessary work.

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 opens with a specific verb and resource: 'Build an unsigned Phoenix limit order transaction.' This clearly distinguishes it from sibling tools like sap_phoenix_build_place_market_order and sap_phoenix_build_place_conditional_order based on the limit-order scope. The reference to returning transactionBase64 for browser approval further clarifies the tool's role.

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 SAP MCP execution guidance gives actionable routing and ordering: call sap_estimate_tool_cost first, then pay/build, and use sap_payments_call_paid_tool if x402 is not natively supported. It also explains the signer boundary and finalization requirement. However, it does not explicitly contrast with market-order or conditional-order alternatives beyond the tool name and the word 'limit order.'

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