Estimate SAP x402 Cost

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

The description states 'Reads escrow/pricing when available' and 'Estimate or fetch state', which implies a read-only operation. However, annotations indicate readOnlyHint=false (not read-only), creating a direct contradiction. The description also does not disclose any behavioral traits beyond what annotations provide, and the contradiction severely undermines transparency.

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 description is three sentences with no wasted words. It front-loads the main purpose and uses straightforward language. Every sentence provides necessary context without redundancy.

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 presence of an output schema, the description does not need to explain return values. It covers the core functionality, optional features, and SAP MCP context. It is mostly complete, though the contradiction with annotations slightly reduces completeness from a behavioral standpoint.

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%, so baseline is 3. The description adds minimal extra meaning by mentioning 'optional volume curve overrides' for the volumeCurve parameter, but does not elaborate on other parameters beyond what the schema already provides. The description adds marginal value over the schema.

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 the tool estimates cost for a number of calls using SDK X402Registry.estimateCost, and mentions reading escrow/pricing and supporting volume curve overrides. It gives a specific verb and resource, but does not explicitly differentiate from siblings like sap_x402_calculate_cost or sap_x402_prepare_payment.

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 using the tool before creating escrows or settling calls, and notes that write operations require signer mode and MCP policy approval. However, it does not specify when not to use this tool or provide explicit alternatives, leaving usage context somewhat implied.

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