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

With no annotations, the description carries the full burden and does so richly: it discloses exact error codes (400/402/503), the payment semantics (refused before settlement so no payment is taken), and the legacy/not-answering status. This is far beyond what structured fields provide.

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?

It is front-loaded with the tool identity and every sentence earns its place by adding an outcome or the alternative. It is slightly dense with clauses but not padded.

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?

For a tool that essentially refuses requests, there is no output schema, and the description compensates by describing exactly what each invocation path returns (error codes and the payment-refusal behavior). It is nearly self-sufficient for an agent deciding whether to call this at all.

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% and the schema already documents sealId as a required UUID while noting productId/serial are not registry keys. The description only reinforces that non-UUID arguments yield HTTP 400, adding marginal value over the schema, so baseline 3 applies.

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 verb/resource ('Legacy x402 seal verify') and distinguishes itself from the sibling verify_record by directing free verification there. However, the phrase 'not answering' leaves the tool's functional status ambiguous - an agent must infer whether the tool ever succeeds, which slightly blurs the stated purpose.

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 explicitly maps argument conditions to outcomes: bad args -> HTTP 400, empty args -> unpaid 402 for discovery, paid call -> 503 refusal before settlement. It also names the alternative ('For free verification use verify_record'), giving the agent a clear routing decision.

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