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

Adds substantial context beyond the annotations: exact price (2.99 USDC, scheme exact), settlement only on completion, and a no-double-charge guarantee with an explicit retry path. The annotations already flag a write/paid operation (readOnlyHint=false, destructiveHint=true), and the description explains the monetary consequence rather than 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?

Front-loaded with the price and mechanism, then the behavior, then the retry rule — a logical order with no filler. The clause 'the same $2.99 scan details as on the website' is mildly redundant with the opening price statement.

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 no output schema, the description covers return values (every check, score breakdown, prioritized fixes as JSON), the two-phase payment protocol, settlement conditions, and retry semantics for a two-parameter open-world tool. An agent has everything needed to invoke it correctly in both phases.

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 description goes beyond the schema by explaining that `payment` is intentionally omitted on the first call and reused verbatim on retries. That adds real semantic meaning to the otherwise opaque base64 PAYMENT-SIGNATURE parameter.

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 verb and resource: runs an AI readiness scan for one website and returns checks, score breakdown, and prioritized fixes as JSON, plus the paid/x402 framing. It is clear what the tool does, but it never names when to prefer it over sibling scan_site or get_report, leaving the boundaries to inference.

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 explicit call sequencing — first call without `payment` to obtain x402 requirements, then call again with `payment` — plus a retry rule with identical arguments on failure or timeout. What's missing is guidance on when to use this paid tool versus the free-sounding scan_site or the get_report sibling.

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