Kimmo:
I'd go for a barred circle over a gorilla with a carpenter's (claw) hammer or one-hand sledge hammer held in his crossed arms. He should also have an evil grin or stupid deer-in-the-headlights blank stare.
FBinNY:
I was a professional mechanic for many years and even taught motorcycle mechanics at Los Angeles Trade-Technical College for five years. And, I assure you that you are correct-- it is the user of the tools that matters.
I've made some goofy field repairs that got folks home or where they needed to go: An Allen wrench & hose clamp to replace a broken shift lever out in the middle of Washington state; a vice grip for a footpeg; a small vice grip & tape to allow use of a broken throttle cable (that was fun to watch). None of these, or other jury-rigged repairs, were on my own bikes. I never let my equipment get that bad.
Some folks should not get near tools. When I rode tubular tires in my racing days (middle of the last century), one had to be able to repair flats by partial disassembly of the tire. There were two guys in my club that were so ham fisted that they never did learn to to do that. I used to charge them to repair their tires. Some folks, for their own safety and the health of others, need to stay out of reach of hammers and sharp knives. ;o)
Joe