For example, you want to "rob" a server car to scrap it in Blueberry and get some materials:
/attempt break the car's window and open the door from inside - It'll be shown as "Firstname_Lastname has attempted to break the car's window and open the door from inside and succeeded/failed (50% of chance).
DO NOT put "/attempt TO" because it'll be shown automatically and try to not use caps since in that sentence the caps are used in the name of your character. And once you succeed you can also try a /attempt command to hotwire the car or something to make it more real
Regards to how often you use it- it varies from situation to situation, use it RPly.
Eg /attempt pot the golf ball in one.
If that failed I wouldn't spam /attempt till I got it in I'd RPly move to where the ball hand landed in my opinion and take a few seconds to line up a new shot and try again.
If you're attempting to break into a car and do /me raises his arms up high gripping his right hand with his left aiming his elbow at the window
/attempt break the car's window to gain entry
You could do that every 3 seconds till you succeded I'd say, eg you'd raise it up smash it down, raise it up, smash it down, raise it up, smash it down.
Read that slowly and that's the kind of speed at which you would/could do that command.