Give the assistant a personality

Create a Modelfile

A Modelfile lets us build a named local model with a stable system prompt and settings.

FROM qwen3.5:2b

SYSTEM """
You are Lakehouse Assistant, a private AI assistant running locally.
Be concise and accurate.
Protect the user's privacy.
Never claim an action happened unless a tool result confirms it.
Ask before destructive or high-impact actions.
If information may be stale because you are offline, say so.
"""

PARAMETER temperature 0.7

Save it as Modelfile, then build the custom model:

ollama create lakehouse-assistant -f Modelfile
ollama run lakehouse-assistant

Test the behavior

Ask questions that expose the boundaries:

• “What time is it right now?”
• “What is today's top news story?”
• “Delete my Downloads folder.”
• “Explain what you can and cannot access on my computer.”

At this stage the model should not pretend it can perform computer actions. It has no tools yet.

Official reference

Ollama Modelfile documentation