Now more to think about what do you carry for road side repairs? puncture what type of pump the short ones can't be much use so are the co2 canisters worth having, or adding Slime or similar
Cheap Chinese pump about 15 inches long, very light, standard puncture repair kit, tyre levers if needed, check before leaving them behind, always Schrader valves, one new unused tube.
A few basic tools according to journey length: Allen keys esp 5mm, small straight and pozi screwdrivers.
Spares on longer trips: one set of brake pads and pliers for the split pin.
Edit:
A spare gear shift inner cable. They last 5-6,000km on my bike, but awkward to lose gears in hilly country!