I have a workbook with messy labels and inconsistent date formats, plus formulas that other people rely on. I’d like to use Claude to help tidy the data, but I don’t want a cleaned-up file that looks right while quietly replacing or breaking formulas.

Has anyone tried this on a real spreadsheet? I’m curious whether you ask Claude to work from a copy, give it a narrow range, or use a different workflow for preserving spreadsheet formulas. What checks do you run before trusting the edited workbook?