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

With no annotations, the description carries the full burden, and it does disclose one genuinely important behavior: the tool is payment-gated and unpaid calls return HTTP 402 at $0.001 USDC. It stops short of describing what a failed settlement or address/amount mismatch produces, or whether the check is read-only and idempotent.

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?

Two short sentences, with the core question front-loaded so the purpose lands immediately. The trailing 'Same resource URL as the REST route' is a developer-facing detail that is marginal but not wasteful.

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?

There is no output schema, so the description should signal what a verification returns (boolean? matched/mismatch detail?) and it does not. The payment-gating note is valuable, but for a 7-parameter settlement verifier with no annotations and no output schema, the description is only minimally complete.

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% across all 7 parameters, including aliases (tx/txHash), amount formats, and the network enum, so the schema does the heavy lifting. The description adds no parameter-level meaning beyond what the schema already states, making the baseline 3 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 names a specific resource and check ('Did this USDC transfer settle to the expected address and amount?'), which tells an agent exactly what it validates. It does not, however, distinguish itself from adjacent siblings like pay_preflight, payto_check, or find_payable, so the agent must infer the boundary.

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 only usage-adjacent sentence covers pricing and transport ('Unpaid calls return HTTP 402 at $0.001 USDC', 'Same resource URL as the REST route') rather than when to call this versus pay_preflight or payto_check. No preconditions, no when-not-to-use, no named alternative.

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