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

Goes well beyond the annotations (readOnlyHint=false, idempotentHint=false): it explains that it holds no key, takes no payment, forwards the header unchanged to POST /nurture/fund, and that only a verified settlement stamps a packet funded. It also discloses the closed-claim-lane refusal and warns against re-paying on timeout — exactly the behavioral context an agent needs for a non-idempotent payment submission.

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 core action and inputs, then layers safety and failure behavior. It is a dense, long paragraph and could be broken into sentences for scanning, but almost every clause carries operational weight rather than 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?

An output schema exists, so return values need not be described, and the description fills the remaining gaps: the upstream dependency on prepare_funding, the settlement-verification model, and the timeout recovery path. For a non-idempotent, funds-adjacent tool this is complete enough to call correctly.

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 already 100%, so the baseline is 3, but the description adds real meaning: xPayment is the standard X-PAYMENT header for an x402 exact-scheme EIP-3009 USDC authorization on Base that the caller's own wallet signed against prepare_funding's challenge. funderWallet is reaffirmed as address-only, never a private key, which reinforces the schema's own caution.

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 — 'Finish funding a packet from your own wallet' — and names the inputs (workId, funderWallet, xPayment). It clearly distinguishes itself from prepare_funding, the upstream step that built the challenge, so an agent can place it in the flow without opening another schema.

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?

Explicit about the precondition (a signed xPayment from prepare_funding), the fallback when it is missing ('refuses and points you back to prepare_funding'), and the failure path on timeout ('do NOT pay again: read work_status first'). This is when/when-not guidance plus the alternative tool to consult.

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