I always carry a multi-tool with me, for slight tweaks while riding. I don't use it much but you'd be surprised how many riders have borrowed it during rides to adjust their, cleats, saddle height/angle, handle bars, fix a broken chain, adjust their brakes, etc.
I can't understand how someone will spend $$$$ on an new bike or new shoes and not have the shop adjust them for fit. Oh well, I have a teenager and he doesn't listen to me either. I carry a small multi-tool made by Lysene and fits under my seat bag.