xlsx-author

xlsx-author

Use this skill when running headless (managed-agent / CMA mode) and you need to deliver an Excel workbook as a file artifact rather than editing a live workbook via mcp__office__excel_*.

Output contract

• Write to ./out/<name>.xlsx. Create ./out/ if it does not exist.
• Return the relative path in your final message so the orchestration layer can collect it.

How to build the workbook

Write a short Python script and run it with Bash. Use openpyxl:

from openpyxl import Workbook
from openpyxl.styles import Font, PatternFill
 
wb = Workbook()
ws = wb.active; ws.title = "Inputs"
ws["B2"] = "Revenue"

Conventions (mirror audit-xls)

• Blue / black / green. Blue = hardcoded input, black = formula, green = link to another sheet/file.
• No hardcodes in calc cells. Every calculation cell is a formula; every input lives on an Inputs tab.
• Named ranges for any value referenced from a deck or memo.
• Balance checks. Include a Checks tab that ties (BS balances, CF ties to cash, etc.) and surfaces TRUE/FALSE.
• One model per file. Do not append to an existing workbook unless explicitly asked.

When NOT to use

If mcp__office__excel_* tools are available (Cowork plugin mode), use those instead — they drive the user's live workbook with review checkpoints. This skill is the file-producing fallback for headless runs.