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

With no annotations, the description carries full burden. It discloses idempotency (replay returns original receipt and cached result, downstream never double-called) and failure handling (failures are receipted evidence, not silence). It also explains the notarization process. It does not cover auth or rate limits, but these are less critical than the stated guarantees.

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, front-loaded with the core purpose, followed by idempotency and failure behavior. 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?

The description covers the essential behavior, idempotency, and failure semantics. An output schema exists, so return values are likely documented. It could mention how to reference services or handle timeouts, but it is reasonably complete for the tool's complexity.

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 0%, so the description needed to compensate. It only explains call_id (idempotent on call_id) and leaves service_id, tool, arguments, timeout_s, request_id, and payment_ref to the schema, which has no descriptions. This is a significant gap for a 7-parameter tool.

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 relays a tools/call to an MCP service and notarizes the exchange with hashes into a tamper-evident receipt chain. It distinguishes itself from siblings like get_receipt and verify_receipts by being the invocation tool that also records evidence.

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?

It provides clear context for when to use this tool: when you need a verified, notarized call to a service with idempotency and failure receipting. It doesn't explicitly exclude alternatives, but the context strongly implies this is the go-to for making service calls that need receipts.

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