I have a CS theory background. If by prompt you mean the full context provided, then there isn’t an effective limit. Claude now has 1M token context windows. You are not going to fill that with just a task specification. You could easily fill it in a large repo with the accumulated design history and total codebase. However this is also largely static, and could be used for fine-tuning. With fine tuning you’re back to a 1M token task specification for the unique variation of this prompt, and recent changes. You are not going to easily fill that.