The prompt is a build step generated by my tool for image->html conversion, which includes APIs the model can call to generate images/patterns/svgs.

https://image.non.io/12275ee8-71e9-4941-823b-e51fec157b4d.we...

The agent is told to generate assets as part of the buildout. It gets to decide what the prompt is for them / whether to do postprocessing like background removal / what type of asset to generate.