Sheets Formulas You Can Actually Read

The formula that works is easy to find online. The one you can debug in six months is not.

That is the gap this drop closes. It is a data & analysis skill built for Gemini, and it takes about ten minutes to set up the first time. After that it runs in under a minute.

Who should use it

Anyone maintaining a spreadsheet someone else built.

How it works

The skill file does five things, in this order.

1. Describe the data shape. Column headers and three sample rows beat any explanation.

2. State the rule in plain words. Including what happens in the edge cases.

3. Ask for two versions. One clever, one readable. Choose the readable one.

4. Demand error handling. IFERROR with a meaningful message, not a blank cell.

5. Get the plain-English note. A comment line explaining the logic for whoever inherits it.

What comes back

A working formula, a readable alternative, error handling, and a comment for the next person.

The mistake to avoid

Paste three sample rows including your messiest edge case. Formulas written against clean example data break the first time they meet real data.

Running it

Save the prompt as a Gem so it is reusable, or paste it into Gemini with your files attached. If the task touches Sheets, Docs or Gmail, run it from the Workspace side panel so it can read the file you already have open.

Where this fits

On its own, one skill saves an hour a week. The compounding happens when three or four of them run in sequence on the same input, the same transcript that produces a scope of work also produces the follow-up email and the project brief. That is the point at which it stops being a prompt and starts being an internal tool. If you want that wired into the systems your team already uses, that is the work 67 Digital does.

In the file

Write a Google Sheets formula for this.

<data>
{paste headers and 3-5 sample rows, including the messiest edge case}
</data>

Rule in plain words: {describe, including what should happen for blanks,
duplicates, text in number columns, and dates in the wrong format}

Give me:
1. The formula, wrapped in IFERROR with a meaningful message.
2. A second, more readable version even if it is longer. Say which you
   recommend and why.
3. A one-line comment explaining the logic for whoever inherits this file.
4. The three inputs that would break it and how it will behave.

Use Google Sheets syntax, not Excel. Prefer LET for anything over 80 characters.