I don't know where you live, but are Swiss Army Knives illegal there because they don't have clips? Is IWB carry with shirt out illegal where you live?
I live in Canada. Like I just said, my understanding is that "it's pretty much the officer's call as to whether or not the knife is a weapon and not a tool. The idea being, a tool is allowed, a weapon is not." Therefore if, for some reason, that officer becomes convinced that you intend to use your swiss army knife as a weapon and not merely as a tool, then yeah, you could be in trouble with said officer. Carrying a knife in the waistband (for example, a small fixed blade with sheath clipped to the waistband covered by a shirt) completely concealed would probably get you in trouble, yeah, but it's hard for me to say. It generally comes down to the discretion of whoever notices you're carrying a knife.
I've had police officers notice the exposed pocket clip of my knife, ask to see the knife to make sure it's not a switchblade or other illegal design, ask me why I carry it, and, satisfied with my answer, give it back to me and go about their business. My understanding is that, because of the ambiguous nature of the criminal code, another officer could do the exact same thing, but instead of being satisfied with my answer, they could suspect that I was carrying the knife for nefarious purposes and I would be in trouble.
The written law is really ambiguous - there is no specific law against carrying knives in general (apart from balisongs, switch blades, and a number of other specific designs as outlined in the criminal code), but carrying concealed weapons is considered illegal.
Confusing, ain't it?
Anyway, I hope I answered your question, but I'm starting to go really off-topic here... The short of it is that I like pocket clips because they help me stay on the good side of my local constabulary. :thumbup: