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

Annotations already declare a safe read, but the description adds material context beyond them: pay-per-call pricing ($0.99 via x402 or Builder/Pro key), a 1 free trial call/day limit over MCP, and an explicit return-scope guarantee that no seller wallet addresses, operator identity, or per-wallet rows are ever returned. Auth requirements and privacy boundaries are exactly the kind of disclosure annotations cannot carry.

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 opening question is a strong hook and the return-field list is compact and front-loaded. However, pricing and access details are interleaved before the core capability, which slightly muddies the front-loading, and the single block of sentences could be segmented more cleanly.

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?

With no output schema, the description must convey return values, and it does by naming the four signal components. It also covers payment and privacy constraints. It stops short of explaining output shape (units, whether 'flagged' is boolean vs score), which would fully close the gap.

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 description coverage is 100% for both parameters, including the 'default 30d' window note and the api_key usage, so the schema does the heavy lifting. The description adds no parameter syntax or format detail beyond what the schema already provides, making the baseline 3 correct.

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 resource and scope: 'wash/circular-settlement signal per facilitator', then enumerates the exact outputs (flagged clusters, flagged volume and share, self-funding percentage, detection date). The subject matter is distinct enough from siblings like get_liveness or verify_before_pay that an agent can route to it without opening a schema.

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?

Usage is only implied by the opening question ('Is this facilitator's volume real, or is it paying itself?'). It never states when to prefer this over sibling signal tools (e.g. get_liveness, verify_before_pay) or any exclusion conditions. The bulk of the text covers billing rather than when-to-use guidance.

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