> they still need tool-trial-and-error dance after injecting them?

It honestly depends on the model. For my pi-brains extension for pi

https://github.com/gitsense/pi-brains

I've found after the first hook injection they get it, but there are occasions it can forget, but since everything is driven by hooks, you can inject as often as needed.

The issue with skills is, they are a one time thing, so you really can't use skills to correct haviorial issues.