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

Annotations already declare readOnly, idempotent and non-destructive, so the baseline is covered. Beyond that, the description discloses real behavioral traits: the call is non-blocking, it stores only a daily pseudonymous actor and normalized reason, and it never stores a wallet, balance, signature or request content, plus it detects incompatible EVM account types before signature. This privacy and detection detail materially exceeds what the annotations provide.

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?

Two tight sentences, front-loaded with what the tool reports and then the safety/detection and data-handling guarantees. Dense but each clause carries distinct information with no filler.

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 should ideally say what the caller receives back from this detection/report, and it does not. It is complete on privacy and behavior but silent on return semantics and on usage relative to sibling preflight tools, leaving an agent with reasonable but not full context.

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 0%, so the description must carry parameter meaning, and it does enumerate the readiness dimensions (wallet, mandate, x402 v2, network, asset, account kind, funding) that map onto the nine inputs. However, it gives no format or value guidance, and the required 'service' and 'intent' parameters are never explained, leaving gaps for a 9-parameter schema.

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?

Names a specific verb and resource: a self-report of wallet, mandate, x402 v2, network, asset, account kind and funding readiness, plus an EIP-3009 compatibility check. This is far more concrete than a tautology. It does not, however, distinguish itself from close siblings such as payment_preflight or preflight, so sibling differentiation is missing.

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 says the call is 'free anonymous non-blocking,' which hints it is cheap and safe to invoke, but it never states when to use this instead of payment_preflight, preflight, or payment_diagnose. No prerequisites, no exclusions, no routing guidance is given.

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