Post Instances Payin Quotes

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

Annotations only declare it is a non-read-only, non-destructive, non-idempotent, open-world call. The description adds genuinely new behavior: quotes expire after 5 minutes (10 seconds for OTC), minimum amounts vary by currency, and OTC quotes have a higher floor. It does not say whether the quote locks a rate or how failures/retries behave beyond the schema's Idempotency-Key note.

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?

Five dense sentences, front-loaded with what the tool does, then the identifier rule, then amount/currency rules, then the funding constraint, then the expiry deadline. No filler and no restatement of the name or title.

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 nested-body POST with no output schema, the description covers the decision points an agent must get right before calling: which wallet id, what unit amounts are in, the ach_pull dependency, and the short-lived nature of the resulting quote. It never says what the quote response contains (e.g. the quote identifier needed for the follow-up payin), which is the one real hole.

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?

With only 33% schema description coverage, the description does real work: it establishes the wallet_id vs blockchain_wallet_id mutual exclusivity, forbids a network parameter, and explains request_amount units (cents) plus currency-dependent minimums and the ach_pull conditional on funding_bank_account_id. Fields like token, currency_type, cover_fees, payer_rules and partner_fee_id still get no semantic help from either source.

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 opening sentence names a specific verb and resource: pricing a payin from a local payment method into a stablecoin wallet. It distinguishes the tool from the payin-creation siblings (Create Payin) but never mentions PostV1InstancesPayinQuotesFx, the closest sibling, so the same-currency vs FX boundary is left implicit.

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 concrete preconditions and constraints: send exactly one of wallet_id or blockchain_wallet_id, never send a network, funding_bank_account_id only when payment_method is ach_pull, and the downstream step ('create the payin with Create Payin before then'). It stops short of routing to the FX quote sibling, which is the main remaining ambiguity.

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