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

With no annotations, the description carries the full burden and does a good job: it discloses the $0.004 cost, accepted payment tokens, the two-step signing flow, and the side-effect that including `payment` completes the purchase inside the call. It leaves some mechanics (e.g., what the 'real sell probe' actually does) unspecified.

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?

Two information-dense sentences with the purpose front-loaded and no filler. Minor ambiguity: 'One call, one 0-100 answer' sits awkwardly against the later instruction to call once without payment and again with payment.

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 paid, two-step tool with no output schema, the description covers the verdict scale, inputs, pricing, payment rails, and the required call flow. It doesn't say what happens when neither `pool` nor `token` is supplied, but the schema already documents the either/or relationship.

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; the description adds value by explaining that omitting `payment` yields the terms while including it completes the purchase within the same tool call. It doesn't add new meaning for `pool` or `token`, but those are already documented in the schema.

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 clearly frames the tool as a buy/no-buy verdict for an Arc pool and specifies the output (0-100 answer) and inputs considered (hook permissions, sell probe, prior buyers). It does not explicitly differentiate from sibling tools like arc_hook_risk or arc_pools, so it stops short of a 5.

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 gives clear usage context ('Should you buy this Arc pool?') and an explicit two-call procedure: call without `payment` to get terms, sign, then call again with `payment`. It does not name alternative tools or exclusions.

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