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

The description discloses key behavioral traits: it is a machine-readable procedure, involves payment of 3 USDT, and includes callback push with poll fallback. This goes beyond the empty schema and no annotations, providing critical context about the autonomous purchase flow. It doesn't mention potential risks like irreversible payment, but the core behavior is well described.

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 a single, dense sentence that packs essential information: machine-readable, autonomous, payment amount, delivery method, and no human in the loop. Every phrase earns its place, and the key details are 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 parameterless tool with no output schema, the description covers the essential context: what the procedure is, what it costs, and how delivery works. It doesn't describe the exact steps or return format, but given the tool's nature as a procedure reference, the description is reasonably complete. It could mention what the agent should do with the result, but this is a minor 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?

The tool has zero parameters, so the schema provides no parameter information. The description compensates by explaining the procedure's purpose and mechanism, which is sufficient for a parameterless tool. Baseline 4 for zero params is appropriate.

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 states the tool's purpose: it provides a machine-readable autonomous purchase procedure for paying 3 USDT and receiving the PRO download without human involvement. It distinguishes itself from siblings like get_pricing and run_free_scan by focusing on the purchase flow.

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 when to use this tool: when an agent needs to autonomously purchase PRO access. It doesn't explicitly state when not to use it or name alternatives, but the context of siblings (get_pricing, get_scan_result, run_free_scan) makes the use case clear. It could be improved by explicitly contrasting with get_pricing.

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