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 two important behaviors: cost (0.01 USDC via x402 on Base) and the failure mode for unpaid calls. It omits the analysis behavior itself — what is returned, whether it is read-only, and what happens with an invalid or unsuccessful receipt.

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 short clauses, front-loaded with what the tool is, then price/payment behavior, then the free alternative. Nothing is padded, though the terseness comes at the cost of the missing analysis detail rather than being purely economical.

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 3-parameter tool with full schema coverage and no output schema, the description covers the commercial and payment-gating mechanics an agent needs to actually invoke it successfully. The remaining gap is what the analysis returns, which is less critical given the schema's thorough parameter docs.

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%, so all three parameters — including the optional legacy payment_signature and its preferred _meta location — are already documented in the schema. The description adds no parameter-level meaning beyond that, which is the baseline 3 case.

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?

"Base USDC receipt wallet flow analyzer" names a domain (Base USDC receipts) and the input object (wallet), so an agent can roughly place it apart from unrelated siblings like textokit_translate_es. But "flow analyzer" is never unpacked: it doesn't say whether it computes net flows, transfer lists, counterparties, or anomalies, and there is no verb describing the action.

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 a concrete operational cue — an unpaid call returns x402 payment requirements, and textokit_sample is the free alternative — which is genuinely useful routing information. It says nothing, however, about when to prefer this over other Base/x402 siblings (textokit_x402_adoption, textokit_x402_ping) or what preconditions the receipt must meet.

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