The problem
How it works
Microsoft added Agent Mode to Excel and Word in Microsoft 365 Copilot, and an Office Agent in Copilot chat that uses Anthropic models to create PowerPoint decks and Word documents. In Excel, you give Agent Mode a request such as a full analysis of a sales data set with visuals. It decides which formulas to use, adds new sheets and charts, then evaluates the results, fixes problems and repeats until it considers the outcome verified. It ends with a summary of its findings and the checks it ran, so you can keep refining. Microsoft says Agent Mode in Excel is built on OpenAI reasoning models and suggests tasks such as a monthly close report, a loan calculator with a payment schedule and a household budget tracker.
Results and limitations
Microsoft’s benchmark chart states 57.2% accuracy for Agent Mode on SpreadsheetBench. Microsoft says it ran the benchmark itself for Agent Mode, Claude and Shortcut, while the OpenAI results were published by OpenAI. This is a vendor claim, it implies that more than four in ten benchmark tasks were not answered correctly, and the post reports no customer outcomes.
Before you try it
At launch Agent Mode in Excel was in the Frontier program for Microsoft 365 Copilot licence holders and Microsoft 365 Personal, Family and Premium subscribers, on Excel for the web, with desktop to follow. The agent’s own validation is not an audit, so check key formulas, totals and assumptions yourself, and work on a copy of the source data. Results depend on your setup and were not independently reproduced by Top 200 Repos.
Tools and repositories
No ranked repository is involved. This use case still stands on its own source.
- Tools
- Excel for the web · Microsoft 365 Copilot (Frontier program at launch)
- Prerequisites
- A Microsoft 365 Copilot licence, or a Microsoft 365 Personal, Family or Premium subscription, with access to Agent Mode in Excel.
Try it yourself: Ask for a checked analysis workbook
Fill the fields to adapt the prompt. Empty fields stay as visible [placeholders].
Using the data in the [Source sheet] sheet, build an analysis that answers this question: [Business question]. Put the calculations on a new sheet, using formulas that refer to the source cells rather than typed-in numbers. Add [Number of charts] charts that support the answer. Then check your work: confirm that totals match the source data, list any rows you excluded and why, and note every assumption you made. Finish with a summary sheet that states the answer, the assumptions and the checks you ran. Do not change or delete anything in the source sheet.Work on a copy of the file and check a few formulas by hand before sharing the results.
Sources
- Vibe working: Introducing Agent Mode and Office Agent in Microsoft 365 Copilot (opens in a new tab)
Vendor post · microsoft.com · Published 29 Sept 2025 · Source checked 12 Nov 2026, 07:54 UTC
What this source supports
- Introduces Agent Mode in Excel and Word, and Office Agent in Copilot chat
- Agent Mode in Excel is built on OpenAI reasoning models and generates, evaluates and fixes outputs in a loop
- For an analysis prompt it chooses formulas, creates sheets and charts, and summarises insights and validation steps
- Benchmark chart states 57.2% accuracy for Agent Mode on SpreadsheetBench; Microsoft evaluated Agent Mode, Claude and Shortcut itself
- Office Agent uses Anthropic models to create PowerPoint decks and Word documents from chat
- Available at launch in the Frontier program on Excel for the web, with desktop coming later