Chelsea manager Mourinho, who views City as the title favourites, said not suspending Toure sent out the wrong message.
Mourinho said: "If he is not suspended, the message is clear: the players can do what they want if the referee doesn't see.
"If there's no suspension, the message is normally that, if the FA defends football, he'd have to be suspended.
"It's the same for everyone: if the referee doesn't see, I can do whatever. It doesn't matter about cameras or others seeing. I can do whatever I want."
The decision not to take action against the Ivory Coast star is a huge boost for City - he could have faced a three-match ban but the three-man panel of former elite referees which reviewed the incident did not unanimously believe it was an act of violent conduct.
That will come as a big relief to City boss Manuel Pellegrini as his club chase the Premier League and FA Cup trophies - including a home match against Chelsea in the Cup this weekend.
Toure, arguably City's most influential player this season, will now be available for Wednesday's game against Sunderland, the Chelsea game and the league fixture against Stoke.
Norwich boss Chris Hughton claimed Toure did kick his player, though said it was a "minimal incident".
The clash happened during the 0-0 draw at Carrow Road and appeared to be missed by match officials.
Hughton said: "It did go unnoticed and there was no doubt there was a slight kick out.
"There was certainly something, but whether that was enough for a red card, then that is for the referee to decide on.
"It was a minimal incident in the game, and the bigger factor was it was a good team performance by us."
There was more good news for City on Monday, with Sergio Aguero and Samir Nasri taking part in a training session after injuries.