2) Have I introduced the main character in a way that makes the reader care? Super important. I know from my own experiences when reading the sample pages on Amazon, that if I don't connect with the MC right off the bat, I'm not going to keep turning pages and certainly won't be buying the book. How to do this then? The easiest way, I think, is to show a vulnerability, a cute quirk, or to hint at their internal conflict – basically give the reader a reason to root for your character and make them human (even if they're orcs, robots or aliens).
3) Have I established the setting? I like to know from the very first paragraph whether I'm in a medieval fantasy world or contemporary New York. I like don't being kept in the dark about the where and when. Similarly, I prefer books not to start with too much setting description so I try to strike a happy medium between the two in my own writing.
4) Does something happen? Well, duh. If nothing happens in the first chapter then I've clearly started the story in the wrong place. The story needs to kick off in the very first chapter because few readers are likely to stick around if nothing happens.
5) Have I established the stakes? This ties in with #1 and #4. By establishing what's at stake for the MC, you will help the reader care about your character while kick-starting the plot. While not all the stakes have to be apparent by the end of chapter 1, there should be enough story and enough character development to show the reader what the consequences will be if the MC does or doesn't get what they want/need.
6) Am I excited by this chapter? If I'm not excited to write the words, readers certainly aren't going to be excited to read them! The biggest test for me comes in revisions months after the first drafting session. If my first chapter doesn't make me fall in love with my story all over again, then it definitely needs some work.
I could add a bunch of other things to the checklist, but I think these are the most salient points for me without getting bogged down in the nitty-gritty of plotting or characterization. There is one last question I ask myself though, and it's one I find almost impossible to answer. Once that first chapter is done and dusted, polished and perfected, I always ask myself, so is the rest of this novel any good? Because a great first chapter is only the beginning that will hopefully lead to a great whole book!