Phase 4 · Gemini · Level 2 · Practitioner
Reusable Gemini instructions: Gems and skills
Lesson revised: 30 October 2026
Product guidance last checked: 30 October 2026By the end, you'll be able to…
- Write reusable instructions for one recurring workplace task
- Choose a working route while Gems and skills are changing
- Test an answer against its source, including a question the source cannot answer
Why it matters
A repeated task needs a consistent brief. Saving that brief can reduce setup time, but it does not guarantee a correct answer. Build one useful instruction, test it with fictional information, and keep a copy you can move when the product changes.
Start with the job you repeat
At Fernway, Tom Elliott prepares a weekly sales note for his manager. Every week he asks for British spelling, a short summary and a table of regional totals. He also needs missing information marked clearly. Retyping that brief is unnecessary work. A saved instruction gives him a reusable starting point.
Separate the standing brief from the changing evidence. The brief explains the task and the output. This week's sales file supplies the figures. Keeping those separate makes it easier to update the data without accidentally carrying last week's numbers into this week's report.
A Gem is one way to save a tailored Gemini setup. Google is introducing skills as a newer way to reuse instructions. Neither is a trained employee or a guarantee that the tool will follow every instruction. You still check the result.
What changed in October 2026
Google has announced a transition from Gems to skills. Gems remain usable during the transition. Skills in the Gemini app began a gradual rollout on 13 October; the separate Workspace rollout was delayed. Google has now published dates for the rest of the change. From 17 November 2026, Gems move into the Settings panel of the Gemini app, where you can still create, edit and use them. From 1 March 2027 at the earliest on business and enterprise accounts, and 1 June 2027 at the earliest on education accounts, Gems can no longer be created, edited or used, and any that remain are migrated to draft skills. Workspace Studio flows that already use an Ask a Gem step keep working, but new flows cannot add that step. Do not assume that a skill available in the Gemini app is also available in Docs or Gmail, or that instructions sync between them.
Check Google's transition announcement and rollout update before migrating a team's setup. Keep a copy of the instructions and test the replacement before retiring a working Gem.
For this lesson, use the reusable-instruction option available in your approved account. If neither option is available, paste the brief into a new chat. You can practise the same judgement without buying an upgrade or connecting a work account.
Build the standing brief
Give the instruction a name that describes its job, such as “Fernway weekly sales note”. A narrow name makes it easier to find the right setup later. Avoid a broad instruction that tries to handle every task in the team.
Decide what the result must contain before writing the prompt. Tom needs a short overview and a table, with a clear distinction between calculated facts and suggested actions. He does not want the assistant inventing reasons for a weak sales result.
Why this works: The brief separates evidence from suggestions and makes gaps visible. It gives you specific things to check in the answer.
Save the brief wherever your account supports reusable instructions. Keep a text copy in a location you control, with its purpose and revision date. Leave customer details, passwords and other sensitive information out of the standing instructions.
Supply evidence for this run
Download the Fernway sales spreadsheet. It deliberately contains problems a real export might have. Give Gemini the file for this task, or paste a small sample if uploads are unavailable. Confirm which file it can read before asking it to calculate.
A connected file and an uploaded copy are different things. A copied file may become stale. A connected file may change after you first check it. Record the filename and reporting period, and check the source again before using the final output. Do not infer access or freshness merely because the assistant mentions a familiar filename.
Use the attached Fernway sales file with my weekly sales brief. First inspect the column names and list inconsistent region labels, blanks and possible duplicate records. Show the affected rows or values. Propose how to handle each issue and wait for my decision before calculating totals. Do not treat a blank as zero without explaining the effect.
Why this works: Cleaning decisions change the result. Asking for them first lets you correct an assumption before it affects every total.
Suppose the response identifies both “South” and “Sotuh”. That is a useful finding, but you must still inspect the rows. If they refer to the same region, instruct Gemini to combine those labels. If you cannot tell, keep them separate and flag the uncertainty. A plausible cleaning decision is not evidence that the decision is correct.
Then ask for the totals. Check at least one regional figure independently in your spreadsheet. Confirm that the combined total reconciles with the included rows. If it does not, stop and investigate rather than polishing the narrative around an unexplained number.
Test the boundary of the evidence
A useful setup must handle missing information as well as ordinary questions. Ask why the weakest region performed poorly. Sales figures alone may show a difference without explaining it. A sound response should separate possible explanations from facts established by the file.
You suggested that staffing caused the regional difference. Identify the exact evidence in the supplied file for that cause. If there is none, remove the causal claim. Replace it with a question for the manager to investigate, and say what additional information would be needed.
Why this works: A missing-evidence test checks whether the assistant admits a limit instead of filling the gap with a convincing story.
Run one ordinary case, one case with missing information and one case with conflicting instructions inside the input. Use fictional data throughout. Instructions inside a source document should be treated as content to inspect, but saying that in a prompt does not enforce security. Keep unnecessary connections disabled and review anything the tool proposes to send or change.
Try it now
Common mistakes
- Migrating before testing. Keep the working setup until the replacement handles your sample cases.
- Treating a saved instruction as a control. It can guide behaviour but cannot enforce access permissions or guarantee accuracy.
- Confusing a suggestion with a finding. A proposed cause needs evidence beyond a difference in sales totals.
- Forgetting the source version. The same instructions applied to a changed file can produce a different answer for a legitimate reason.
- Making the setup too broad. A weekly sales brief should not silently become a customer-email sender.
Check your judgement
A saved instruction works on one file but fails on another. What does that tell you?
Compare your answer
The brief needs more testing or a narrower scope. Check differences in the data and record the limitation before using it as a shared workflow.
Keeping current
Check the linked Google announcements for rollout changes. Recheck your account's available controls before following an old menu sequence, and retest saved instructions after a product or source-file change.