Spreadsheet Formula and Cleanup

Before: A common reply: a formula with A1:A10 placeholders that you have to translate to your own layout.

After (skill output, from a real test run): Test run on 8 rows of a public passenger CSV, Excel 365. Asked for surname, title and average-by-class age fill. Output, unedited: "M2: =LEFT(D2,FIND(\",\",D2)-1)" and "O2: =IF(F2=\"\",ROUND(AVERAGEIFS($F$2:$F$9,$C$2:$C$9,C2),1),F2)", plus a table of all 8 rows with expected and computed values (row 7: 21.3 = average of the other class-3 ages), and a note that it was recomputed in Python, not run in Excel.

Tell it what you want the sheet to do, paste a few real rows and name your app (Excel 365, older Excel, Google Sheets, LibreOffice). You get a formula in your real columns, a short explanation, a test table on your sample rows, edge cases, and what it could not verify. For messy data it gives numbered cleanup steps that start with making a copy.

What you can check yourself. The sample result on this page, the list of what is in the file, and the 30-day refund. There are no ratings yet, because nobody has reviewed it yet.

How we tested it.

2 runs on a public CSV (Claude Sonnet). The first run left out the test table, so we made that section mandatory; the second run included it and the numbers matched.

Tested on a real example before release. The example is shown in the Before and after section above.

How we test, what we do not do, and which assistants we ran it on.

• It does not open Excel or Sheets. Its test is a recomputation from your sample, and it says so.
• It only knows the rows you show it. Odd values elsewhere in the sheet can still break a formula.
• Some functions need Excel 365 or Google Sheets. It names the limitation and gives a fallback.
• It does not edit your file. You paste the result in.

Works in ChatGPT or any chatbot: you paste in your details and it writes the result. No script needed. If your assistant can run Python, it uses it to check the formula on your sample.

1. Unzip the download. It holds the spreadsheet-formula-and-cleanup folder, a README and the licence.
2. Put the spreadsheet-formula-and-cleanup folder where your assistant looks for skills. The generic path is .agents/skills/ (or npx skills add from a folder). Tool-specific paths:
   • Claude Code: ~/.claude/skills/ (or .claude/skills/ inside one project)
   • OpenAI Codex, Gemini CLI, Cursor and others: .agents/skills/ or the skills folder their docs name
   • claude.ai: zip the skill folder yourself, then Customize, Skills, the plus button, Create skill, Upload a skill (code execution must be on in Settings, Capabilities)
   • ChatGPT or any chatbot: open the skill's prompt.md, paste it into the chat, then paste your own text or link
   • Steps for each tool, with links to its official docs: how to install Agent Skills
3. Ask for the job in plain words, for example: "In Excel 365, in this sheet (columns: ...) I want ... Data starts in row 2.". The skill loads by itself.