I HATE a story that starts with dialogue. If I don't know who's talking or who they are talking to or I get thrown in in the middle of a conversation ... I just. don't. care. Seriously. It's the quickest way for me to flick over to the next story.
I HATE looooooooooooong descriptions and backstory and infodump in the first paragraph. I. also. just. don't. care.
Of course, THE most important thing you can do with a story, in my opinion, is nail the first paragraph. You can do either of the above but you HAVE TO DO IT WELL. You need to hook your reader and you have the length of that word count to compel them to keep on reading. If I hate your first paragraph, I'm grumpy when I read the second one, I have half an eye on the room or my email inbox or my shopping list by the third and by the fourth, I know I am rating this a 2 and I'm only continuing to ease my own guilt.
None of this, of course, applies if you happen to be brilliant. Thing is though, if you happen to think you are brilliant, this greatly reduces the chances of you actually being so.
Here's an example ... I have read so many detective style stories in my slushing and in my LSS time that I CANNOT stand them. Most people do them as an homage and they don't do them very well. The irony doesn't work. The puns and the send ups look awkward. The stories look dated and are painful to read. Yet, I read Neil Gaiman's "Four and Twenty Blackbirds" on the weekend, which is set in the 50s detective style. It plays it straight. And it also works with nursery rhymes which, if you've read a lot of Jasper Fforde ... also is becoming "done before". Of course, Gaimain IS a brilliant storyteller and writer and he not only pulls it off but he rejuvinates the love of that particular story.
Most writers are not in Gaiman's league. But I read Gaiman and when I read your story, I compare it to his because that's the point of LSS and a Year's Best.
Harsh but true.