当一个 AI agent 要为一张发票或者是合同付款的时候，它怎么知道这个凭证里面的内容（如收款地址、金额）是真的还是假的？依据是什么？ When an AI Agent intends to pay for an invoice or a contract, how does it know if the contents in there, such as the recipient address or amount, are authentic or not? What is the basis for its action?