When Claude Audits a Spreadsheet, Does It Fix Anything?

Ask Claude to audit a spreadsheet and it is tempting to picture it finding the errors and quietly fixing them while it is in there. The video explains that this is not what happens. Anthropic's audit-xls skill finds and reports problems, citing them by cell, but it never rewrites a formula.

Fix it or report it

The common guess is that "audit" includes repair. The video says the skill does not work that way. It audits a spreadsheet for formula accuracy, errors and common mistakes, and reports what it finds, cited by cell. If you give it a sheet with a formula you already know is broken and then look at the sheet afterward, the formula is untouched. What changed is the report, not the spreadsheet.

What it checks, and in what order

The skill checks the balance sheet first. The reasoning is that if the balance sheet does not balance, everything downstream is suspect. After that, it scans the scoped range, sheet or model for formula accuracy, errors and common mistakes. The scope matters: the audit covers what it is pointed at, and it does not decide what counts as an error beyond its own checks.

One mismatch, four stops

The video follows a single example, a balance sheet that is off by a fixed amount. The steps run in sequence. The balance check comes first, the mismatch is found, the affected cells are cited, and a finding is reported. Then the skill stops. Nothing is rewritten, and the finding waits for you to look at it.

What a clean or flagged result does not mean

Two cautions follow from the example. A clean balance sheet pass does not mean the whole model in scope is error-free. It only clears that one check, and formula errors elsewhere are checked separately. In the other direction, a balance sheet imbalance flag does not mean every downstream number is individually wrong. It means those numbers are unverified until the imbalance is resolved, not confirmed incorrect. In both cases, nothing in the sheet has been changed.

Finding versus fixing

The video closes by dividing the work. Finding the problem is Claude's job here, and fixing it stays yours. The audit flags every suspect formula by cell, but a person decides what to change and whether a flagged item is actually wrong.

Key takeaways

• The audit-xls skill reports problems and cites them by cell; it does not rewrite formulas.
• It checks the balance sheet first because an imbalance makes everything downstream suspect.
• After the balance check, it scans for formula errors and common mistakes in the chosen range, sheet or model.
• A clean balance sheet pass clears only that one check, not the whole model.
• An imbalance flag means downstream numbers are unverified, not confirmed wrong.
• The spreadsheet is unchanged until you act on the report.
• Fixing the problem remains the user's job.

Try it yourself

Give Claude a spreadsheet with one formula you already know is wrong, and ask it to run the audit-xls skill: check balance first, then scan for formula errors and report what it finds by cell. Afterward, open the sheet and check whether the formula itself changed. Looking at the sheet after the run is the quickest way to confirm that the skill reports rather than repairs.