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

Goes well beyond the annotations: it discloses the paid model (0.10 USDC x402 exact on Base mainnet), the shared 10-call free tier over 30 days, that every call requires X-Wever-Wallet-Proof bound to the exact JSON arguments and API path, and that no private keys are accepted. The readOnlyHint and idempotentHint are confirmed rather than contradicted, and the custody/funding caveats add genuine invocation-relevant context.

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?

Core purpose and scope are correctly front-loaded in the first two sentences, but the remainder mixes necessary call metadata (fee, auth) with legal/trust boilerplate ('A disbursement primitive, not a bank…', 'External custody and security audit required…', 'Company-authored') that does not help an agent invoke the tool. Roughly 11 sentences is oversized for a 2-param read.

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 read-only tool with no output schema, the description covers scope, auth, pricing and custody adequately, and defers return/authorization detail to /api/payout-contract. It still lacks any statement of what a returned receipt or error condition looks like, leaving a modest gap.

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 the parameter burden. It identifies both lookup keys and clarifies that idempotency_key refers to the original create key, but it omits the po_ pattern/format and does not resolve the oneOf requirement semantics (required list is empty). Partial compensation only.

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 first sentence names a precise verb (Read) and resource (a payout and its signed transition receipts) plus the two lookup keys. The clause 'Read-only: no payout state change, signing, reconciliation or transaction submission' cleanly routes it away from the write siblings (payout-create/authorize/execute).

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?

It makes clear this is the read path for an existing payout and points to /api/payout-contract for schemas and the authorization flow. It never explicitly names a sibling alternative or an exclusion condition, so the routing is contextually implied rather than stated.

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