It's very important to me to have pairings and warnings clearly identified. There aren't many things I won't read, but there are a few things, especially shota. I want the ability to avoid these stories or else I feel the urge to flame the author, not for the content, but for not warning me of the content.

Pairings are important too - not because I care about seme/uke, but because there's a pairing I will do my best to avoid.

A poor summary will keep me from reading a story, especially if it contains poor grammar and/or spelling.