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

With no annotations, the description carries full burden. It discloses the paid nature, the payment response flow (retry with `_meta['x402/payment']` carrier or `x402_payment` fallback), and fail-closed behavior on conflicting carriers. Also explains it returns drift history and corroboration, setting expectations for output.

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 dense but all sentences contribute: value proposition, differentiation, payment processing, and an example. The structure is front-loaded with the paid warning and usage trigger.

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?

Given the payment complexity and existing output schema, the description covers purpose, usage, payment flow, fallback, and gives an example. The only minor gap is api_key, but the output schema exists for return details.

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 has 0% description coverage, but description explains the `url` parameter via example and the `x402_payment` fallback in detail. `api_key` is left undocumented, though its name and default are self-explanatory. This compensates for most, but not all, parameters.

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 this is a paid preflight check for agent endpoint safety, returning live checks plus drift history, corroboration, and an explicit allow/caution/block verdict. It clearly distinguishes from the free sibling `guild_preflight` by explaining what the deep version adds.

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?

Explicitly tells when to use: when asking if an endpoint is safe to call or detecting drift before delegating/paying. It also explains the free alternative remains available and why this paid version is needed (change detection and corroboration), including payment retry mechanics.

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