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

With no annotations, the description carries the full burden, and it does disclose the most consequential trait: the call costs 0.01 USDC. It also reveals the outcome space (allow/review/block). It does not say whether the fee is charged on failure, what thresholds distinguish review from block, or whether the check itself mutates anything.

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?

Front-loaded with the legacy/cost warning and the migration pointer, then the check list, then the sibling routing. Dense but every clause carries information; the repository URL takes up space but is warranted by the deprecation notice.

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 7 parameters and no output schema, the description does the essential work of naming the return verdicts and the validation dimensions. The main residual gap is decision semantics: what makes a result 'review' versus 'block' is left unstated.

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%, so baseline is 3. The description adds real meaning by explaining the expected_* parameters collectively as a change-detection baseline ('detects recipient/network/price changes against caller expectations'), which tells the agent why all three exist together rather than as isolated fields.

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 (payment preflight) and enumerates exactly what is validated: HTTPS destination, EVM payTo format, Base network, amount validity, and drift detection against expectations. It also names the verdict it produces (allow/review/block) and explicitly separates itself from vendor_preflight.

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?

Gives clear steering away from this tool for new integrations (use the local SDK) and names the alternative for deep KYB checks (vendor_preflight). The positive trigger is only implied by 'LEGACY', not stated as a condition, so it falls short of full when/when-not coverage.

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