My touring bikes have a bottle cage below the downtube, for around home I have a toolbag in that cage with a tube, the toolbags were sold with that cylindrical shape for that purpose. Some peanut butter jars also fit those cages, such as older Skippy jars before they started making smaller jars. I spray painted the insides of some old skippy jars that fit well with black paint so it is not obvious what is in them. I also have some plastic bags in the tool bag or jar to put on my saddle if I am caught out in the rain.

When on tour, I use all water bottle cages for water bottles. I carry the spares and tools in a pannier.