Your agent is not free to do anything he or she chooses on your behalf. An agent's relationship to the principal is that of a fiduciary. This means the agent is in a position of trust and confidence. He or she has a duty to act in the best interest of the principal. Although an agent has this duty, you still need to be careful of your choice for an agent. You should not execute a power of attorney unless you have complete faith in that person.
You not only need to have faith that your agent has your best interests at heart, but also that he or she has the ability and knowledge to manage your financial affairs. The agent in a power of attorney could have the ability to cause great financial damage. It is true that you can sue your agent for misuse of the power of attorney, but you may not be successful and it is difficult to recover what you may have lost even if you prevail.