I'm going to offer a completely unscientific opinion, and say that it depends on your target audience.
We have readers who come here to be titillated, who are interested in the sex, and the kinkier the better. Stories are no more than wank fodder for these readers, and that's fine. They are the readers who look for tags that suit their interests, and will click on and read anything with the appropriate tags.
Then we have readers who want plot, and they are willing to wait for the sex as long as they're engaged by the author, and feel like the characters and plot are compelling. These readers might offer reviews that suggest plot developments or pairings, but they aren't motivated solely by the sex. They might even read a story tagged No-sex if the summary is compelling enough.
The tags I think are crucial in a summary are the pairing tags (M/F; M/M; F/F; 3Plus) because some readers are not fond of certain gender pairings, and get irritable if they encounter slash when they expected het, and the trigger tags (Minor1/Minor2; Incest; Rape) because these particular content markers are the ones we'll hear about fastest if they're missing.
My suggestion is to write a short (150 words or less) blurb about your story. Then distill that to one strong sentence of Twitter length. That sentence is your summary, and leaves you enough space for the most crucial codes. Use the longer summary as the AN in the first chapter. We allow up to 600 words, but 150 is a good length without becoming boring. If you have oral sex cropping up in chapter 3, you can add a line at the top: "Additional Warnings: Oral" and no one can say they were not warned. That's entirely within the guidelines here, and in fact, it works well for many of our authors who hate giving away too much with tags.