So much implicit information is developed and checked by coming up with the answers around who, what/how, and why, that people can often do what they need to do with just that. The rest of it is tools for generating additional alignment when that turns out not to be quite enough by itself.
The other question you'll be asking about a story is "is this more important than that?"
It's very important that question be satisfied, so you can prioritize, and reprioritize as your understanding changes.