What problem does it solve? Building and editing Excel workbooks programmatically is error-prone: formulas break, columns clip, charts misrender, and cached values go stale. This Skill provides a complete, QA-driven workflow for producing professional .xlsx files through the OfficeCLI tool, covering everything from CSV import to financial-model formatting standards. ## Core Features & Use Cases - Workbook creation and editing: Set cells, formulas, number formats, column widths, named ranges, charts, pivot tables, conditional formatting, and data validation via OfficeCLI commands. - Reading and analysis: Inspect existing workbooks with outline, text, annotated, and HTML views, plus CSS-like queries to find formula errors, broken references, and placeholder tokens. - Financial modeling standards: Enforces industry color coding (blue inputs, black formulas, green cross-sheet links), number formatting conventions, and assumption documentation. - Use Case: Import a 600-row sales CSV, add a revenue summary with SUM formulas and a column chart, apply currency formatting and print layout, then run the full QA cycle to deliver a board-ready workbook with zero formula errors. ## Quick Start Ask the assistant to create an Excel workbook from your data or to read and analyze an existing .xlsx file, and it will use OfficeCLI to build, format, and validate the result.