Building Custom AI Assistants with Gems

What are Gems?

Gems are customized versions of Gemini designed for a specific purpose.

They allow you to:

• Predefine instructions once;
• Reuse the same behaviour without retyping prompts;
• Create specialised AI tools for different tasks.

Why Gems Are Useful

Instead of repeatedly explaining how you want Gemini to behave, a Gem lets you “lock in”:

• Instructions;
• Tone;
• Output style;
• Default behaviour.

This makes your workflow faster and more consistent.

Using Prebuilt Gems

Gemini includes ready-made Gems such as Storybook, which can:

• Generate illustrated stories;
• Turn images into narrative content;
• Adapt tone and style based on input.

You can also use images as input to personalise outputs (e.g. creating storybooks based on photos).

Creating Your Own Gem

You can create a custom Gem by defining:

1. Name and Description

• Name defines its identity;
• Description explains its purpose.

2. Instructions

These are the core rules the Gem follows every time, such as:

• Output style (e.g. realistic, creative, formal);
• Constraints (e.g. colour rules, perspective, tone);
• Behaviour guidelines (e.g. how to interpret inputs).

3. Default Tools

You can set a default mode for the Gem, such as:

• Image generation;
• Text-based responses;
• Other specialised outputs.

This ensures consistent behaviour without extra prompting.

Refining Gems

Once created, Gems can be:

• Tested immediately;
• Adjusted by editing instructions;
• Improved iteratively for better output control;
• Saved and reused anytime;
• Shared with others.