Pencil, pocket knife, tape measure, straight edge, drawknife/machete/hatchet(for roughing), ferriers rasp, 12” bastard file (smoothing over corners), stout straight scraper for majority of tiller work that I can put some weight into, curves scraper for funky staves, Sand paper and a flat board for good glue lines on overlays, and a chainsaw file for nocks are what I use to make everything. And still need a fine bastard file, sharpening stone, burnishing rod and oil to keep everything sharp. I can reduce the tools to machete, ferriers rasp, scraper, pocket knife, tape measure and pencil and still not have a difficult time. The scraper and rasp are just for clean lines. So a bare minimum for a usable bow is a pencil and machete/hatchet since you can use it as a scraper to tiller and clean lines. The measurements can be done with body measurements.
Kyle