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

Annotations already declare the tool read-only, idempotent, and non-destructive. The description adds concrete behavioral detail beyond the flags: it returns the x402 v2 PaymentRequired document and enumerates its contents (amount in USDC base units, network, asset, payTo, request schema), plus notes the tool is free. This enriches the bare annotation profile without contradicting it.

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 one front-loaded sentence that starts with the action 'Returns', followed by a focused list of returned fields and a two-word sentence 'Free.' There is no filler or repetition of schema details, and every clause contributes meaningful information.

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 zero-parameter, no-output-schema, read-only tool, the description covers the purpose, response content, and cost. It does not explain workflow ordering relative to sibling tools, but that is minimally necessary for invoking this simple endpoint correctly. The 'request schema' reference is slightly underspecified but acceptable.

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 and schema coverage is vacuously 100%, so there are no parameter semantics to clarify. The baseline for a 0-parameter tool is 4, and the description's enumeration of returned fields provides useful context without needing to explain inputs.

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 and resource: 'Returns the x402 v2 PaymentRequired document for the paid Flash Audit'. This clearly distinguishes it from siblings like buy_flash_audit and collect_flash_audit, which imply transactional actions, and check_contract_free, which is about free contract checks. The resource is unique and unambiguous.

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?

There is no explicit when-to-use guidance or alternative routing. The phrase 'for the paid Flash Audit' implies it applies to paid audits, but it does not say 'use this before buy_flash_audit' or contrast with check_contract_free. An agent is left to infer the appropriate context from sibling names alone.

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