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: it discloses the $0.002 per-call cost, accepted payment assets and chains, the pre-payment refusal of invalid inputs, the two-call payment handshake, and the guarantee that launch data comes from a real index and is 'never guessed'. This is unusually rich behavioral disclosure.

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 ('Token info... before showing it') and the payment mechanics, with no filler sentences. The field enumeration is dense and long, but each item maps to an actual return value, so it earns its place.

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?

No output schema exists, so the description must describe return values — and it does, listing the exact fields an agent receives. Combined with the payment flow, pricing, and refusal behavior, nothing needed to invoke it correctly is missing.

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 the baseline is 3, but the prose adds real meaning to `payment`: it explains that the value is a signed x402 payload placed in PAYMENT-SIGNATURE and that passing it completes the purchase inside the call. The `token` parameter is only mirrored, not enriched, so not a 5.

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?

States a specific verb+resource ('Token info for an Arc token') and enumerates the exact data returned — metadata, provenance via a launch index, pool price/liquidity, and risk signals. An agent can distinguish it from siblings like arc_price or arc_pools because it bundles token metadata with launch provenance and risk in one call.

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 clear operational context: use it 'before showing' a token, wallet/non-token inputs are refused before payment, and the exact two-step x402 flow (call without payment to get terms, sign, call again with payment). It does not explicitly compare against alternatives like arc_touchstone or arc_verdict, so it falls just short of a 5.

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