What is the term for the rights that allow a particular action to be taken on someone else's behalf?

The term that describes the rights allowing a particular action to be taken on someone else's behalf is known as Power of Attorney. This legal document grants an individual the authority to act for another, making decisions regarding financial, legal, or medical matters. It is a formal agreement that can empower one person, referred to as the agent or attorney-in-fact, to manage the affairs of another person, who is known as the principal, thus creating a trusted fiduciary relationship.

Power of Attorney is specifically designed to ensure that the person designated has the necessary authority to take action in place of the principal, which can be vital in various scenarios, such as when the principal is incapacitated or unable to make decisions. The scope of this power can be broad or limited, depending on how the document is drafted.

While other terms like Legal Authority and Agency Agreement also relate to permissions granted between parties, they do not encapsulate the specific legal authority conferred through a Power of Attorney. Direct Authorization might suggest permission granted for a specific action, but it lacks the formal structure and ongoing authority represented in a Power of Attorney. Therefore, Power of Attorney is the most appropriate and precise answer to this question.