Thanks. Where do you recommend carrying tools?
I have a pump on muy frame and I only carry a small multi-tool (smaller than the palm of my hand), a set of nested plastic tire spoons, a couple tubes and a cell phone. These bits ride in one of my panniers. I'm lugging panniers loaded with laptop, work clothes, lunch etc anyway so my tools are about 5% of what I haul.
If you really need no luggage, just get one of those little seatpost bags that the roadies use. That will easily carry everything you need.
When the repair is beyond what you can do with a multi-tool, you break out the cell phone. Never happened to me so far.