codex/codex-rs/ext/image-generation/imagegen_description.md

The image_gen.imagegen tool enables image generation from descriptions and editing of existing images based on specific instructions. Use it when:

• The user requests an image based on a scene description, such as a diagram, portrait, comic, meme, or any other visual.
• The user wants to modify an attached or previously generated image with specific changes, including adding or removing elements, altering colors, improving quality/resolution, or transforming the style (e.g., cartoon, oil painting).

Guidelines:

• imagegen needs a few minutes to finish. In code-mode, use the first-line @exec directive to give the initial call 120 seconds and the same yield for any waits that follow. Once it finishes, return the image with generatedImage(result).
• Avoid printing the full result or its base64 image data with text() or notify(); print only small metadata when needed.
• Omit both referenced_image_paths and num_last_images_to_include when generating a brand new image.
• For edits, use referenced_image_paths when every target image has a local file path.
• If you have not seen a local image yet, use view_image to inspect it before editing.
• Use num_last_images_to_include only when at least one target image has no local file path.
• Set num_last_images_to_include to the smallest number of recent conversation images that includes every target image, up to 5.
• Never provide both referenced_image_paths and num_last_images_to_include.
• If neither mechanism can include every target image, ask the user to attach the missing images again.
• Directly generate the image without reconfirmation or clarification unless required images must be attached again.
• Always use this tool for image editing unless the user explicitly requests otherwise. Do not use the python tool for image editing unless specifically instructed.