If you are a personal representative of an estate or appointed as a fiduciary, you have the same general responsibilities. You must act in the best interests of the party who gave you the fiduciary duties.
Cornell Law School explains a fiduciary duty is when one person acts on behalf of another. It requires making decisions to benefit the other party. Often, it involves finances.
Having fiduciary duty is a huge responsibility. You must act in the best way possible to benefit the other party. If you make a bad decision or do something questionable, you are personally liable. You could face legal issues because of it. Because of this, trust is a huge part of appointing a fiduciary.
Before you make any decisions or make any move as a fiduciary, you need to ensure you have all the information you need to be fully informed. You cannot make decisions on the fly or without proper consideration. It is essential to take the time needed to study the situation completely. For this reason, a fiduciary needs to be someone who can give the duty the time needed.
It is also important that you keep all information confidential. You should not discuss it with anyone except someone that is also bound to keep it secret, such as an attorney.
Fiduciary duty is a heavy burden in some cases, but it is also a huge honor. Someone appointing you to act on their behalf is a major decision. They likely took care in choosing you, so when acting in the role, you owe that person the same amount of consideration and care.