Google Gemini prompt guide

How to prompt Google Gemini

1. Use Google's four parts: persona, task, context, format.
2. Keep the prompt precise and direct; drop heavy prompt-engineering scaffolding Gemini 3 doesn't need.
3. Write in full natural sentences, as if briefing a colleague.
4. Answers default to terse and efficient; ask explicitly for a conversational tone or more detail when wanted.
5. With pasted data or long files, put the data first and the question or instruction last.
6. Define any ambiguous term or success criterion explicitly.
7. Use consistent delimiters (Markdown headings or XML-style tags) to separate instructions from material.
8. List constraints (tone, length, must-include items) in their own block, separate from the task.
9. Add concrete keywords: dates, places, numbers, names, timeframes.
10. For current facts, ask it to use Google Search and give sources; mention Gmail/Drive files by name with @ when relevant.
11. Split multi-part jobs into separate prompts or a numbered list of deliverables.
12. For deep investigation, use Deep Research rather than a long single prompt.

The shape of a good prompt

[Persona: You are a ...]
[Task: one clear verb-led instruction]
[Context/data: background or pasted material]
[Constraints: tone, length, must/never items]
[Format: bullets, table, headings, word count]
[Final question or instruction placed after any long data]

Avoid

• Bare keyword prompts ('marketing talking points')
• Over-engineered meta-prompts written for older models
• Instructions buried above large pasted data
• Several unrelated tasks crammed into one message
• Assuming chatty output without asking for it

Example

Request plan a 3 day trip to rome

You are an experienced travel planner.

Task: Create a 3-day itinerary for Rome.

Context: Two adults, first visit, mid-range budget, staying near Termini station, travelling in late October. We enjoy history and food and prefer walking or public transport.

Constraints:
- Group sights by neighbourhood to limit travel time
- Include booking tips for sights that need tickets
- Suggest one lunch and one dinner spot per day

Format: For each day, a table with Time, Activity, Notes. End with 5 bullet points of practical tips. Use Google Search to check current opening hours and note anything uncertain.