How to Set Up Custom Instructions for Gemini in Workspace

You know that moment when you ask an AI to help you draft an email, and the first thing you have to type is "make it shorter, no jargon, friendly tone"? You say it every time. And the AI forgets it the next conversation. Custom instructions are how you fix that — you write the rule once, and the AI remembers it for every future conversation in that Workspace account.

Gemini (Google's AI assistant built into Google Workspace — the bundle of Gmail, Docs, Sheets, and the rest) recently expanded this feature to more apps. What started in Google Docs now works in the side panel of Slides, Sheets, and Gmail, plus the standalone "Ask Gemini" boxes in Drive and Chat. Here's how to set it up and use it well.

Before you start

You'll need a Google Workspace account with Gemini included. That usually means a paid Workspace plan with the Gemini add-on, or a personal Google AI plan that bundles Workspace access. If you're on the free consumer side of Google (gmail.com without Workspace), the feature may not appear the same way. Open one of your Workspace apps first — Docs, for instance — and look for a small ✨ Gemini icon. If you see it, you're good to continue. If you don't, the rollout may not have reached your account yet, or your plan doesn't include it.

Step 1 — Open the Gemini side panel

Pick any Workspace app where Gemini shows up. Google Docs and Gmail are the easiest starting points.

• In Docs, click Extensions in the top menu, then Google Workspace, then Gemini.
• In Gmail, look for the ✨ Gemini icon in the right-side toolbar and click it.
• In Drive, click a file, then look for Ask Gemini at the top of the file list.
• In Sheets or Slides, the ✨ icon usually sits in the right sidebar.

You'll know it worked when a chat-style panel slides out from the right side of your screen with a text box at the bottom.

Step 2 — Find the customization area

Inside that side panel, look for a gear icon ⚙️, a three-dot menu ⋮, or a label like "Settings", "Customize", or "Saved info". Google has renamed this area a few times, so the exact word may be different from what you expect.

Click it, then scan for any option that mentions "custom instructions", "personal preferences", or "how Gemini responds". If you don't see one in the side panel, try opening Gemini's main site (gemini.google.com) while signed in to your Workspace account — the same instructions often live there under Settings.

You'll know it worked when you see a text box labeled something like "Tell Gemini how to respond" or "Your personal preferences."

Step 3 — Write your first instruction

Here's the part most people either skip or overthink. Don't try to write the perfect instruction on day one. Start with one rule that solves a problem you actually have. A few patterns that work well:

• Tone — "Always reply in plain, conversational English. No corporate jargon."
• Length — "Keep responses under 150 words unless I ask for more."
• Format — "Use bullet points for any list with more than three items."
• Role — "Treat me as a small-business owner, not a corporate employee."
• Language — "Default to US English. Use the date format Month Day, Year."

Type one instruction, save it, and close the panel. That's it for now.

You'll know it worked when you come back tomorrow, open the same panel, and the instruction is still there — not reset, not empty.

Step 4 — Test it on a real task

Open a fresh conversation (start a new chat so the instruction isn't buried under older context) and give Gemini an actual job you needed done this week. A messy email reply. A summary of a long document. A formula for Sheets.

Watch the response. Did Gemini follow your rule? If you asked for short replies and got three paragraphs, the instruction may have been saved but not loaded — try signing out and back in, or editing the instruction to make it shorter and clearer (very long instructions sometimes get partially ignored).

Step 5 — Add more rules as you notice patterns

After a week, you'll start noticing things you keep re-typing. Every one of those is a candidate for a custom instruction. Some real examples people add later:

• "When drafting emails, always include a clear next step or call to action at the end."
• "For Sheets formulas, add a short comment above each formula explaining what it does."
• "When summarizing documents, lead with the conclusion, then the supporting points."

Don't pile in 20 instructions at once. Add two or three, live with them, then add more.

You'll know it worked when you stop typing those rules in your prompts.

Step 6 — Use it across apps (the actual superpower)

Here's what changed recently: that one set of instructions now follows you across the Gemini surfaces in Workspace. The rule you wrote for "always bullet points" will apply when you ask Gemini to summarize a file in Drive, draft a reply in Gmail, or rewrite a paragraph in Docs. You don't have to set it up five times.

If you want different behavior in different apps (say, more formal in Gmail, more casual in Chat), there isn't a per-app switch today — you write one instruction set for your whole account.

Common mistakes

• Writing a whole essay. Instructions longer than a short paragraph start losing effect. Keep it under about 300 words total.
• Conflicting rules. "Always be brief" and "always give detailed answers" can't both win. Pick one direction.
• Forgetting to test. Saving instructions and never opening Gemini again means you'll assume they don't work, when in fact you just haven't tried.
• Assuming it carries to other Google accounts. Custom instructions are tied to the Workspace account where you set them. Sign in to a personal Gmail, and Gemini won't know your preferences.
• Not coming back to edit. Your needs change. Re-read your instructions every few months.

Wrap-up

Custom instructions are a small feature with outsized payoff. The first time you open Gemini and it just knows to keep replies short, or to bullet-point lists, or to skip the corporate fluff — that's the moment it starts feeling like a real assistant instead of a tool you have to keep teaching.

Try one rule today. Add a second next week. Let the rest build up on their own.