He should never be overaggressive or timid. The Miniature Schnauzer is generally sweet, loving and loyal. They often have a favorite person, even though they will love the whole family. They will bark when someone comes to the door. Properly trained, though, they will stop when the owner indicates that the person at the door is welcome and not a threat.
Schnauzers are generally intelligent and learn quickly.
Many have excelled in formal obedience trials. They are seen more and more in agility competitions also. Miniature Schnauzers are eligible to participate in Earthdog Trials and some excel at them. Schnauzers shed very little. They tend to cause fewer and less severe reactions in people allergic to dogs than breeds that shed more.