I first saw @GillyBarr's tool holder model.  That got me looking at all the Mini tool holders.  Of course, none were exactly right for me.  Here's mine.

The clip-in attachment was inspired by this model by @adamos_76250.

Designed to be printed with 0.4mm nozzle, 0.2mm layer height.  I printed it in PLA.

I set the slicer to three perimeters.  Most of the walls are thin enough that only two perimeters are used, but upping to three make the clips sturdier.

The design includes a place to use an M4x8 machine screw to expand one of the clips to “clamp in” the holder.  As it turns out, the clips hold well enough that I found the screw to be unnecessary.

The 大力 ("Dairiki" — my surname —  in Japanese) visible in the photo is not included in the STEP or STL files.