How to reduce the risk of a bank returning an international payment

Which documents and formulations reduce the probability of an international payment return: counterparty verification, correct payment purpose, consistency of contract, invoice, and amounts, and prepared-in-advance explanations.
Why the bank requests the economic purpose of the operation

Why the bank requires explanations for international payments, what information reveals the operation’s business purpose, how to describe goods, services, counterparty, and settlement chain for currency control and compliance.
What documents are needed to pay an import contract

List and logic of documents the bank expects for import contract payment: contract, invoice, specification, supplier data, product description, and operation economic justification.