An annoyance is not accepting "close enough" answers, I was working an older puzzle from a few days ago and the answer was `pulls` and I was trying `pull`. I tried a few other things, clicked for the clue (first letter was `P`), tried `pull` again (does that count against my characters when I repeat failed answers?), tried `pulled`, then finally got `pulls`.
Echoing angry_moose's suggestion, a hint about the # of letters (on mouseover?) would help a lot. Or maybe that would make it too easy?