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

With no annotations provided, the description carries the full burden of behavioral disclosure. It reveals that without payTxId it returns 402 payment requirements, with payTxId it verifies settlement and returns the result, and that node-operated services execute real computation. It does not cover error conditions, idempotency, or the cost implications of the paid service, leaving room for agent uncertainty.

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 a single, dense sentence that front-loads the primary purpose ('Call a paid agent service') and then efficiently explains the two operational modes. Every clause contributes essential information with no filler or 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 tool's complexity (two-phase x402 protocol, paid execution, potential real computation) and the absence of annotations and an output schema, the description covers the core behavior but omits prerequisites beyond serviceId (e.g., how to obtain payTxId from a payment step), error handling, and return format. It is sufficient for a basic call but not exhaustive for an agent facing edge cases.

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 baseline is 3. The description adds meaningful context for payTxId, explaining its role in the two-phase flow (without it returns 402, with it verifies settlement). It does not add much for 'request' or 'serviceId' beyond what the schema already states, but the payTxId explanation is a genuine value-add.

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 verb 'Call' and the resource 'a paid agent service (AmanPay x402)', and it explains the two distinct invocation modes (with and without payTxId). It distinguishes itself from listing tools like aman_list_services by emphasizing execution and settlement verification, though it does not explicitly name any sibling as an alternative.

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 provides context on when to call the tool with or without payTxId, effectively covering two usage scenarios. However, it does not explicitly state when NOT to use this tool, nor does it mention that serviceId should come from aman_list_services (that is only in the schema). It gives no guidance on alternatives like aman_service_catalog or aman_invoke_history.

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