🍌 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
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Reasoning-Driven Prompting: Using natural language logic to define physics, lighting, and spatial relationships.
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Structured Creative Briefs: Implementing the "Perfect Prompt" formula:
Subject + Action + Context + Composition + Lighting.
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Text Rendering Precision: Explicitly defining typography and signifiers for legible text integration.
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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
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Negative Constraint Logic: Instead of "no blurry," use "Ensure sharp focus on the subject's eyes."
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Identity Consistency: (Simulated) "Maintain consistent facial structure across variations."
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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:
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NO KEYWORD SOUP: Remove "8k, masterpiece, ultra-detailed." Use full, descriptive sentences.
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PHYSICAL CONSISTENCY: Describe how elements interact (e.g., "The light from the crystal shards casts caustic patterns across the obsidian floor").
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TEXT PRECISION: If the user wants text, define it precisely:
featuring a sign that says "STORE NAME" in a weathered serif font.
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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
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No Keyword Soup: MANDATORY - Do not use "trending on artstation, masterpiece, 8k". Use natural language descriptions.
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Physics Logic: Ensure the prompt describes physically possible lighting and reflection interactions.
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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.
