Have A Target
When you find yourself on a big team that's been given an abstract goal with a poorly defined target - refuse to participate. If you don't know what you're doing or why or how it's going to be used or who it's going to be used by, then you can't do anything. You can only guess about how to build a thing you'd use that's in the ballpark of what will hopefully be requested, but you can't be sure.
If you can't find someone who can clarify your target for you, keep asking. If no one exists that can clarify - or they do exist but they just don't know - then you're doing something unimportant and should ask to be reassigned.