Man, no wonder you guys don't vote enough, you're seriously overthinking things...
- vote up questions you think are good
- vote down questions you don't think are good
The tooltips are just that: tips. They're not definitive, legalistic definitions of when you must up or downvote, they're just short summaries of the most likely reasons you'd consider a question to be good or bad.
I may come back and add more later, but this really shouldn't need a long answer.