XLSX skill: what it does and how to install it

What it does. Creates, edits, analyses and converts Excel workbooks and spreadsheet files using openpyxl or pandas, with markitdown for quick inspection. It preserves workbook conventions, builds formulas and formatting, documents assumptions, and runs LibreOffice recalculation to check for formula errors.

When to use it. Use it when an .xlsx, .xlsm, .xltx, .csv or .tsv workbook is the primary deliverable, including financial models and multi-sheet cleanup. It does not cover Word, HTML reports, standalone Python scripts, database pipelines or Google Sheets API work.