I reckon primitive toolkits were passed along just the way toolkits are these days. It takes a while to make up the tools that you need to even make the tools that you need to make any finished article.
Last night I sat gluing flint flakes into old POC arrow shafts, playing with thicknesses for drill bits. Nothing primitive about it except for the tips but it was still worthwhile.
I've got antler knapping tools cut with hacksaws, square edges on stone adze handles
, all sorts of in-betweens but they're all practice pieces really. By making them up with modern tools you find out the tools that you need then go back a stage, make up the new tools then start over on the main piece again.
Wouldn't be like that in a real primitive society. You'd start from an earlier age and have tuition, apprenticeships and the likes.
Fun trying though, each step back is a step forward
.