Which Sci-Fi Story?

Premise: short science fiction story from the 50s - only humans write fiction, and they are sought for this reason by all in the galaxy. Fiction is exported to everyone, all of it, however, prompt written by AI's - ranging from the very cheap to very expensive models, creating a variety of bad to sometimes good fiction - but these machines can also be tinkered with to make them better.

Spoiler: One very poor author breaks into a very successful colleague's house in the hope of stealing his AI-settings - but discovers that this person's AI is broken and that the successful stories are all written by hand.

Please: Which title, author and year?