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

With no annotations, the description carries full behavioral disclosure. It prominently reveals the $0.10 USDC pay-per-call cost, the required payment-signature header, the error behavior without payment, and the narrow JSON-only scope. This is strong transparency about side effects and preconditions.

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?

Four dense sentences, each serving a distinct purpose: what it verifies, what it returns, its scope, and its payment/auth behavior. No filler or repetition; the most critical action is front-loaded.

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 verification tool with no annotations and no output schema, the description covers the main operational needs: purpose, output shape, scope, cost, and auth failure behavior. It does not detail what 'acceptance rules' may include or how the evidence packet is structured, but the schema example provides additional payload guidance.

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 tool description adds meaningful context by defining the JSON-only verification scope and the entities involved (offer, request, payment receipt, deliverable, acceptance rules), which helps the agent construct an appropriate query beyond the schema's generic 'question or input' phrasing.

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 states a specific verb ('Verify') and a clear resource ('a paid deliverable against its offer, original request, payment receipt, and acceptance rules'). It lists concrete outputs (ACCEPT/REJECT/REVIEW verdicts, reason codes, booleans, hashes, evidence packet), which fully distinguishes it from the marketing/content sibling tools.

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 gives clear context on when to use the tool: verifying paid deliverables within a JSON-only scope and requiring a payment-signature header. It does not explicitly name alternative tools or state when not to use it, so it stops 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.