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

The description goes well beyond the readOnlyHint/idempotentHint annotations by explaining the exact verified=true contract, the failure modes (CONFIG_ERROR, retryable UPSTREAM_ERROR), and the guarantee that failures are never reported as silent verified=false. It also clarifies the privacy boundary: only public data is exposed, never keys.

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 front-loaded with the core purpose and is internally organized, but it includes extraneous implementation history ('the follow-up to which intentionally split the on-chain proof logic... to avoid file collisions across parallel sessions') and a cryptic reference to 'hard rule 1'. These details add noise without helping an agent select or invoke the tool.

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, the annotations, and the presence of an output schema, the description is complete: it defines success conditions, error behavior, optional-parameter semantics, access gating, and data-privacy constraints. An agent has enough context to call this tool correctly and to interpret its verified result.

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 carries the full parameter-documentation burden. It compensates thoroughly for signatures, since_iso, signature_limit, and expected_usd, explaining their behavior and interactions. Only caller_id is left undocumented, but it has a default and appears to be a minor field.

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 opening sentence states a concrete and specific purpose: proving on-chain that the treasury received settled x402 USDC. This clearly distinguishes the tool from generic verifiers like verify_transaction and verify_token by naming both the asset class and the settlement domain.

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 gives clear operational guidance: omit signatures to auto-fetch recent ones, or pass an explicit list to bypass the DB lookup. It also explains the free-read access posture. It does not explicitly name alternatives to choose between, but the usage logic is specific enough to be actionable.

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