What Would Make an AI Book Creator Genuinely Useful?

There are many AI writing tools available today, but not all of them are practical for long-form content like books.

What features would make an AI book creator truly valuable for you?

Examples:

• Better chapter outlining

• Maintaining a consistent writing style

• Faster drafting without sounding generic

• Built-in publishing or formatting support

What would you personally expect from an AI book creator before you would rely on it?