(a) Except as otherwise provided in a power of attorney, an agent is not required to disclose receipts, disbursements, or transactions conducted on behalf of the principal unless ordered by a court or requested by the principal, a guardian, a conservator, another fiduciary acting for the principal, a governmental agency having authority to protect the welfare of the principal, or, on the death of the principal, by the personal representative or successor in interest of the principal's estate.