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

With no annotations provided, the description carries full responsibility for behavioral disclosure. It transparently states the $0.004 per-call cost, the two-step payment process (terms first, then signed payment), and the data provenance guarantee ('Facts from the chain, never a label'). It omits rate limits or explicit read-only status, but the key behaviors are well covered.

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 purpose question, followed by a compact list of metrics, then cost and payment steps. Every sentence contributes value—purpose, outputs, provenance, pricing, and invocation flow—with no filler. The metric list makes it slightly longer than strictly necessary, but each item sharpens the tool's scope.

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 no output schema, the description provides a solid overview of the return content (trading metrics and flags) and fully explains the required input and payment workflow. It doesn't specify the exact response structure or define 'flags', but the description gives enough for an agent to understand what to expect and how to execute the two-step call.

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 meaningful workflow context beyond the schema: it explains that calling without `payment` returns terms and that passing the signed `payment` completes the purchase. It also ties the `address` parameter to the trading-profile purpose, enhancing the schema's dry field description.

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 opens with a specific question—'Who is this Arc address as a trader?'—and then enumerates concrete outputs: first-buyer frequency, entry speed, USDC in/out, stuck positions, and flags. This is a clear, specific purpose that distinguishes it from generic wallet or reputation tools, even without naming siblings.

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 implies the use case (profiling a single Arc address's trading behavior) and gives detailed invocation steps for the x402 payment flow: call without payment for terms, sign, call again with payment. However, it never explicitly contrasts with sibling tools or states when not to use this tool, leaving alternatives unaddressed.

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