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

Goes well beyond the annotations by disclosing that it reads only the call material with no network, fetch, money movement, message, sharing, config change or external write, states the exact price ($0.10 USDC via x402 exact) with ten free signed-wallet calls per rolling 30 days, requires X-Wever-Wallet-Proof bound to the arguments and route, and notes an Ed25519 signed receipt. The annotations already cover readOnly/openWorld/destructive status; the pricing, auth binding and receipt details are the real added value. Minor gap: the description does not clarify the interplay with idempotentHint=false for repeated identical submissions.

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 purpose, then the output/verdicts, then behavioral constraints, pricing, and finally contract/page links. The density is high but every block adds information; the only mild excess is listing out the full set of prohibited behaviors, which is still valuable for trust. It is long, but proportional to a paid, signed-report tool.

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 paid tool with nested parameters and no output schema, the description covers what to submit, what the report contains (average ticket, share of value in payments >= $1, churn signals, unanswered questions), the possible verdicts, payment terms, auth binding and receipt signing. Nothing an agent needs to call it correctly appears to be missing.

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 only 50%, so description must compensate, and it does: it enumerates every field, gives concrete examples ('196M', '$42M'), explains buckets as 'count or value' and that a size distribution is optional, and clarifies that transactions/settled_value are the core required metrics. It leaves a few schema fields (unique_payers/unique_payees, asset) without elaboration, so it is not exhaustive.

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 action and resource: submit a payment-metrics summary (transaction count, settled value, buckets) and get back a signed report with a verdict among churn_shaped, distribution_needed or value_backed. The scope is unambiguous. It does not explicitly name a sibling it differs from, so sibling differentiation is only achieved through verb/resource specificity rather than an explicit contrast.

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 tells the agent what input to assemble (transaction count, settled value, optional asset/window/payers/payees, buckets) and what output it yields, which implies the usage context. However, there is no explicit when-to-use versus when-not-to-use guidance, no alternatives named (e.g. fair-value or spending-anomaly checks), and no prerequisites beyond the wallet-proof note.

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