All of Chewy's stuff plus 2 sets of metric combi spanners, side cutters, socket & bar for the prop nut and a 12v test lead.
Although not tools, I also carry a roll of insulating tape, small coil of electric cable, a handful of cable ties, a couple of jubilee clips, spare fuses, spark plugs, and a roll of duct tape (I own a Searider
You can get screwdrivers and basic tools from the pound shop, which are ok for keeping on the boat for emergency use.
A tool roll is handy to keep them in. You can then keep this in a flare box, dry sack, tupperware box, freezer bag, ......