“Do you have a pen?” … After a few minutes the answer is “Sorry, no.” What if the question would have been “Do you have something to draw with?”. Maybe a pencil, or chalk could have been found. And better yet, “I need to draw. Do you have a pen?” This signals not only the need, but also a prefered set of properties on the solution. These properties are not requirements, but can still be used as input.
Does your requirements process work like this? Or do you have “Must Have”, “Could Have” and “Nice to Have”? It is the need, and the implied and fuzzy priorities, that is the essential part of agile requirements management work. These are seldom articulated in standard requirements mangement processes.