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 well: it discloses pricing ($0.003/call), the accepted x402 payment rails (USDC on Arc/Base/Solana, XNT on X1), the payment handshake, and the provenance of the verdicts (first 60 swaps of the first two minutes, earliest 12 buyers' funders). This is exactly the behavioral context an agent needs before paying to call.

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?

Front-loaded with the purpose and the value proposition, then the payment mechanics. Dense but nearly every clause carries a distinct fact; the parenthetical on swap/buyer sampling is long but justifies the trust claim.

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 one-parameter, no-output-schema, paid tool, the description covers everything needed to call it correctly: cost, accepted currencies, the sign-then-resubmit flow, and what the returned verdicts mean and where their raw evidence lives.

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?

Only one parameter, and schema coverage is 100%, so the baseline is 3. The description goes beyond the schema by explaining the semantics of omitting `payment` (returns terms) versus supplying it (purchase completes in-call), which is the key operational distinction the schema alone does not convey.

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?

Names a specific resource (real-time Arc launches / new pools) and states precisely what each result carries: a sell verdict from a real round trip and a bundle verdict. It also implicitly differentiates itself from arc_bundle_check by naming it as the place the raw evidence lives, so the agent can tell the summary tool from the evidence tool.

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?

Gives explicit invocation instructions, including the two-step handshake (call once without `payment` for terms, sign with your own wallet, call again with `payment`). It does not, however, state when to prefer this over siblings such as arc_pools or arc_exit_check, nor any exclusions.

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