Build SAP x402 Headers From Escrow

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

The description adds context like SDK method name and flow position beyond annotations. However, it is ambiguous whether the tool performs writes: it says 'fetching escrow data' (read) but annotations mark readOnlyHint=false, suggesting possible writes. The description does not clarify side effects or state modifications, leaving agents uncertain.

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?

Three sentences, no fluff, first sentence states purpose and method, second gives context, third provides guidance. Ideal conciseness for an agent.

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?

Given the tool has an output schema (not shown but present) and full schema coverage, the description covers high-level usage context and flow. It does not explain error conditions or prerequisites (e.g., existence of escrow data), but is adequate for a builder tool.

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?

Input schema covers all 3 parameters with 100% description coverage. The description adds no additional semantics about parameters (e.g., format, defaults, or constraints beyond schema). Baseline score is appropriate.

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 clearly states it builds SAP x402 HTTP headers by fetching escrow data, using a specific SDK method. It distinguishes itself from sibling tools like sap_x402_fetch_escrow (which fetches but does not build headers) and sap_x402_settle_batch (which settles). The verb 'build' and resource 'HTTP headers' are specific.

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 advises to use this tool before creating escrows or settling calls, placing it in the payment flow context. It warns that write operations require signer mode and policy approval. However, it does not explicitly say when not to use it or compare with alternative tools for pre-payment steps.

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