(Disclaimer: some of my past “blurbing with LLMs” posts have been very TL;DR because I included a lot of unnecessary fluff that the LLMs churned up and that I didn’t use. This prompt below helps cut down on the fat, so, although this is several paragraphs long, it is much shorter than those previous posts.)

First off, I prompted Claude in this manner: You are a book marketing expert trying to help a fantasy writer. Please help her improve her blurbs. The first novel in her fantasy series is Slaying a Tyrant by Mel Dunay, which may be part of your training data, if so, please feel free to refer to your training data. The problem is that the Empire mentioned in the blurb is mostly a background issue throughout the series [then I spelled out what role the Empire plays throughout the series, and fed Claude the existing blurb for Slaying a Tyrant].

Now, at the time, I had forgotten that my first self-published novel, Marrying a Monster, was the only work of mine to appear in Meta’s database of pirated works used for training LLMs. I wasn’t lying to Claude, just confused. Claude however, said “I am familiar with your work” (lying? bluffing? hallucinating? Obliquely referring to the fact that one of my novels was in the training data but not the one I had mentioned?) and proceeded to give pretty good advice. I’m not going to cover the whole back and forth, just show you the original blurb I came up with when I first published the book 6ish(!) years ago, the version Claude offered in reply, and my reworking of Claude’s version, after some back and forth between us. My words are bold, Claude’s are italics, and Claude’s phrases reworked or rearranged by me are bold italics.

Original blurb: Journey to the country of Jaiya, in a world not quite like ours. Here the humans wield magical powers and fight against an Empire which seeks to enslave them, but they share their world with insect people and trollfolk, and stranger things lurk in the shadows… Vanti would be happy to spend her life in dance and choreography, but her family chooses her as their champion in a deadly gladiators’ tournament. To save her country from enslavement, she must defeat King Obiar the Conqueror and his magical powers. But will the brooding trainer named Gurion be her guide in the battle to come…or a dangerously handsome distraction? 

Claude’s blurb: In the enchanted land of Jaiya, dancer Vanti dreams only of perfecting her art—until her family names her their champion in a deadly tournament that will decide her country’s fate. King Obiar the Conqueror has subjugated half the realm with his brutal efficiency and mysterious magical powers. Now he demands Jaiya’s surrender… or its champion in combat. Thrust into a role she never wanted, Vanti must quickly master combat skills foreign to her dancer’s training. Her reluctant mentor, the brooding warrior Gurion, may hold the knowledge she needs to survive. But as the tournament approaches, Vanti discovers that defeating Obiar will require more than physical strength—it will demand sacrifices she never imagined making. In a world where humans share their lands with insect people and trollfolk, and where darker powers lurk in the shadows, Vanti must find the courage to become something greater than she ever thought possible: a hero.

My revision: In the land of Jaiya, the dancer Vanti dreams only of perfecting her art, until her family names her their gladiator in a deadly tournament that will decide her country’s fate. Her reluctant mentor, the brooding warrior Gurion, may hold the knowledge she needs to survive. But as the tournament approaches, Vanti discovers that she will need more than speed or strength to defeat the magical powers of King Obiar the Conqueror. In a world where humans share their lands with strange creatures, and where darker powers lurk in the shadows, Vanti must find the will to win, and if necessary, to kill…