How to write the data section when data is reused from a previous work?
If the context is that of a three-paper dissertation, my opinion would be to refer to the earlier paper which has the thorough description. You should ask your supervisor to be sure, but a collection of essays allows that. A monograph type thesis is much preferable.

If the context is that of a journal submission, then each paper must be stand-alone and the data must be described in according detail. A self-citation is allowed, and some common phrases will save you time, but you cannot self-plagiarise and some rewriting is necessary. You can have one paper being more detailed than the other but the less detailed paper must still contain enough information. So yes, you should describe your data twice.