"Limited pet" can often mean a pet that you can't control and which has a specific duration of life (like until the mob dies). I can't speak for SKs but in the case of wardens, we get three of them... one is a pack of attack dogs that we launch and forget - they attack the targeted mob until the mob dies or until the mob kills them. So they are kind of like a DoT with nice animation!
Both of the other two are healing bots - one is a "healing tree" which lasts for a specific length of time or until it is killed by a mob and heals anyone standing within it's area of influence. The other is a healing fairie who heals nearby group members, again, for a specific period of time or until killed by a mob. Both of these are also launch and forget and are like HoTs with nice animation!
Neither one is really a pet.
"Well, my days of not taking you seriously are certainly coming to a middle."
~ Mal Reynolds