Gemini Vision Skill | Agent Skills

Gemini Vision

Analyse images with Gemini's vision capabilities. Pass one or more images and a prompt; the model returns a detailed text answer.

Requirements

GEMINI_API_KEY environment variable set
uv available

Quick usage

# Describe an image
uv run ~/.claude/skills/gemini-vision/scripts/gemini_vision.py \
  "Describe this image in detail." \
  photo.jpg

# Answer a specific question about an image
uv run ~/.claude/skills/gemini-vision/scripts/gemini_vision.py \
  "What text is visible in this screenshot?" \
  screenshot.png

# Compare two images
uv run ~/.claude/skills/gemini-vision/scripts/gemini_vision.py \
  "What are the differences between these two images?" \
  before.png after.png

# Extract structured data from a chart or table
uv run ~/.claude/skills/gemini-vision/scripts/gemini_vision.py \
  "Extract all values from this bar chart as a Markdown table." \
  chart.png

# Control the model and output format
uv run ~/.claude/skills/gemini-vision/scripts/gemini_vision.py \
  "List every product name and price visible in this photo." \
  --model gemini-2.5-flash \
  shelf.jpg

Options

| Flag | Default | Description | | -------------- | ------------------ | --------------------------- | | --model | gemini-2.0-flash | Gemini model to use | | --max-tokens | 4096 | Maximum output tokens | | --system | (none) | Optional system instruction |

Supported image formats

JPEG, PNG, GIF, WEBP, BMP, TIFF, PDF pages (single-page PDFs work as images).

The script auto-detects MIME type from the file content (not the extension).

Common prompts

| Goal | Example prompt | | ---------------------- | -------------------------------------------------------------- | | General description | "Describe this image in detail." | | OCR / text extraction | "Extract all text visible in this image." | | Chart / graph data | "Convert this chart to a Markdown table." | | Diagram explanation | "Explain the architecture shown in this diagram." | | Accessibility alt-text | "Write a concise alt-text for this image." | | Comparison | "Compare these two images and list the differences." | | Receipt / invoice | "List every line item, quantity, and price in this receipt." | | UI screenshot | "Describe the UI elements and layout in this screenshot." |

SDK notes

Uses the new google-genai package (not the deprecated google-generativeai):

# ✅ Correct
import google.genai as genai
from google.genai import types

# ❌ Deprecated
import google.generativeai as genai

Multiple images are passed as a list; the model sees them in order:

contents = [
    types.Part.from_bytes(data=img1_bytes, mime_type="image/jpeg"),
    types.Part.from_bytes(data=img2_bytes, mime_type="image/png"),
    "Your prompt here",
]
response = client.models.generate_content(model=model, contents=contents)
print(response.text)

Agent Skills: Gemini Vision

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