🍌 Nano-Banana Expert Skill (Gemini 3 Style)

A specialized skill for AI Agents to leverage "Reasoning-Driven" image generation.

Based on the advanced prompting architecture of Google's Gemini 3 (Nano Banana Pro), this skill moves beyond keyword stuffing to structured, logic-based creative briefs.

Core Competencies

Reasoning-Driven Prompting

Using natural language logic to define physics, lighting, and spatial relationships.

Structured Creative Briefs

Implementing the "Perfect Prompt" formula:

Subject + Action + Context + Composition + Lighting

.

Text Rendering Precision

Explicitly defining typography and signifiers for legible text integration.

Contextual Grounding

Using "Search Grounding" logic (simulated) to anchor generations in real-world accuracy.

🏗️ Technical Specification

1. The "Perfect Prompt" Formula

Component

Description

Example

Subject

Detailed entity description

"A stoic robot barista with exposed copper wiring"

Action

Dynamic interaction

"Pouring a latte art leaf with mechanical precision"

Context

Environment & Atmosphere

"Inside a neon-lit cyberpunk cafe at midnight"

Composition

Camera & Lens choice

"Close-up, 85mm lens, f/1.8 aperture"

Lighting

Mood & Direction

"Volumetric blue rim light, warm cafe glow"

Style

Aesthetic anchor

"Cinematic, photorealistic, 4K production value"

2. Advanced Features

Negative Constraint Logic

Instead of "no blurry," use "Ensure sharp focus on the subject's eyes."

Identity Consistency

(Simulated) "Maintain consistent facial structure across variations."

Text Integration

Use double quotes for specific text:

The sign reads "OPEN 24/7"

.

🧠 Prompt Optimization Protocol (Agent Instruction)

Before calling the script, the Agent MUST rewrite the user's prompt into a logic-driven Reasoning Brief:

NO KEYWORD SOUP

Remove "8k, masterpiece, ultra-detailed." Use full, descriptive sentences.

PHYSICAL CONSISTENCY

Describe how elements interact (e.g., "The light from the crystal shards casts caustic patterns across the obsidian floor").

TEXT PRECISION

If the user wants text, define it precisely:

featuring a sign that says "STORE NAME" in a weathered serif font

.

OPTICAL DIRECTIVES

Specify lens behavior: Shallow Depth of Field (f/1.8) , Macro Lens , Anamorphic Flare . 🚀 Protocol: Using Nano-Banana Step 1: Define the Creative Logic Provide the agent with a subject and a specific scenario. Step 2: Invoke the Script The generate-nano-art.sh script translates the logic into a structured Gemini 3-style prompt.

Generating a reasoning-driven image

bash

scripts/generate-nano-art.sh

\

--subject

"a glass chess piece"

\

--action

"shattering into liquid shards"

\

--context

"on a obsidian table"

\

--style

"macro photography"

⚠️ Constraints & Guardrails

No Keyword Soup

:

MANDATORY

- Do not use "trending on artstation, masterpiece, 8k". Use natural language descriptions.

Physics Logic

Ensure the prompt describes

physically possible

lighting and reflection interactions.

Full Sentences

The model parses relationships; use "light reflecting off the water" instead of "water, reflection". ⚙️ Implementation Details This skill applies a "Logic Wrapper" around the core/media/generate-image.sh primitive, converting fragmented inputs into a coherent, reasoning-ready narrative prompt.