Andrew,
For 50 cents I got a collapsable umbrella with case at Goodwill, threw away the umbrella.
It fits in that slot behind the handlebars, held with two small bungies.
I just carry an adjustable wrench, a 10/11 mm box, needlenose pliers, one of those 6 in 1 screwdrivers, and allens assortment. You can cram a lot more tools in there if you like.
You don't carry the weight, and the whole assortment cost a few bucks.