An agenda could also be an ulterior motive or hidden purpose, as when we say of someone: "I think she has a political agenda." In this sense, the agenda is not what I want to accomplish, but where I want the field to go, an ideological stance or bias.
In Spanish, the word agenda means a small appointment calendar or "planner." So the agenda is also what must be done during particular days, hours, and weeks. That's an interesting metonymy.