🍌 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.