The most important words are not your book’s opening lines. They are not found inside the book at all. They are your book’s description on Amazon.

As an author of six published historical novels, I’m embarrassed to admit that I only just discovered this critical information. In the lead-up to the release of my latest, Enchantress: A Novel of Rav Hisda’s Daughter (Plume, Sept. 2014), my webmistress sent me a link to an updated version of my site, and I was appalled to find a strange and inaccurate description of my novel there. When I asked—demanded, actually—where this synopsis came from, she said, “I got it off Amazon.”

To my astonishment and horror, there it was on my book’s preorder page. It was a description I’d written and sent to my editor a year earlier, but the story had changed significantly by the time I’d finished it. This was a calamity!

These days, not only do potential online buyers check Amazon, but those who frequent bricks-and-mortar bookstores do, too. Worse, Goodreads displays Amazon’s descriptions, and many online library catalogues use Goodreads.

When I pointed this out to my editor at Plume, she asked me to craft a new one as soon as possible. But instead of opening Word, I went back to Amazon. I’d noticed that not all of my current description appeared on the screen. Rather, it ended abruptly with the phrase, “Click here to read more.” It was the same for other books.

When you create copy for a brochure or back cover, you assume that every word will be visible. With that in mind, the final sentence is made as intriguing as possible, to leave a lasting impression. Yet on Amazon, that all-important final sentence will probably not be read.

Pleased at recognizing this, I figured I could simply count the words on a few Amazon descriptions to determine how long mine should be. But they were all different, ranging from 119 to 145 words. I checked character count too, only to find that it varied even more.

Clearly Amazon utilized some undecipherable method of deciding where to cut off a description. So I examined a larger sample to determine the average word count, which came out to 130. For safety’s sake, I decided I would craft my description slightly shorter.

So I needed to create a new description that packed its biggest punch in the first 120 words, whose next few sentences were interesting as well, and was long enough to fill the allotted space on my Web page. Plus, I had to do it ASAP, before too many people saw the old one.

After spending an entire day writing what I believed was a decent substitute, I sent it off to my agent, publicist, freelance editor, and webmistress. They provided criticism and suggestions, and so I rewrote. This process was repeated several times before I had 176 polished words to send to my editor at Plume, who displayed her editing chops by improving it yet again.

Here’s what we ended up with: “Fantastic tales of demons and the Evil Eye, magical incantations, and powerful attractions abound in Enchantress, a novel that weaves together Talmudic lore, ancient Jewish magic, and a timeless love story set in fourth-century Babylonia.” (On Amazon, the previous paragraph is in bold.)

“One of the most powerful practitioners of these mysterious arts is Rav Hisda’s daughter, whose innate awareness allows her to possess the arcane skills men lack. With her husband, Rava—whose knowledge of the secret Torah enables him to create a ‘man’ out of earth and to resurrect another rabbi from death—the two brave an evil sorceress, Ashmedai the Demon King, and even the Angel of Death, in their quest to safeguard their people, even while putting their romance at risk.”

The text above is 117 words long, so the next two lines might appear on the product page, depending on the browser: “The author of the acclaimed Rashi’s Daughters series and the award-winning Rav Hisda’s Daughter: Apprentice has conjured literary magic in the land where abracadabra originated. Based on five years of research and populated with characters from the Talmud, Enchantress brings a pivotal era of Jewish and Christian history to life from the perspective of a courageous and passionate woman.”

I sighed with relief, until I realized I still needed to fix the Amazon descriptions of my previous five novels.

Maggie Anton is a Talmud scholar, with expertise in Jewish women’s history, and the award-winning author of Enchantress: A Novel of Rav Hisda’s Daughter and the Rashi’s Daughters series, published by Plume Books. She lives in Los Angeles.