Agency is the ability to take actions that positively affect one’s life. Not to be confused with autonomy, which is self-direction and the freedom to take action. A prisoner may have agency but not autonomy. Agency is akin to effectiveness. It is the opposite of helplessness. It is related to an internal locus of control. Self-efficacy is the degree to which one believes that one has agency. That is, belief in one’s ability to achieve intended results.
Resources:
https://en.wikipedia.org/wiki/Self-efficacy
https://en.wikipedia.org/wiki/Locus_of_control