Jon Daly, still playing as a trialist as his new club wait for a transfer embargo to end on September 1, opened his account with a double after Lewis Macleod and Andy Little set the ball rolling with first half goals.
Robbie Crawford then struck early in the second half and Daly's brace was sandwiched between a superb finish from fellow new recruit Nicky Law.
"I'm delighted. The best way I feel we show teams respect is to play them in the same manner. It couldn't have been any better," McCoist told BT Sport.
"It's important as we need to get goals and confidence in the team and give the rest of the teams a reminder that if they are not up to scratch we will punish them.
"If you are not up to doing your job you will be punished. The level of commitment and skill over the 90 minutes was really pleasing."
And things look set to get even better for McCoist come the start of next month, when he has even more players to pick from.
"We have been delighted with the boys we have got but won't get carried away," McCoist said.
"Once September comes and we have a full selection of players...we are quite excited.
"It's going to be a lot of competition for places. At the moment the boys are showing what they are all about."