Yes I agree with all of that.

The way I let my agents interact with my code bases is through a 70s BSD Unix like interface, ed, grep, ctags, etc. using Emacs as the control plane.

It is surprisingly sparing on tokens, which makes sense since those things were designed to work with a teletype.

Worth noting is that by the times you start doing refactoring the agents are basically a smarter google with long form auto complete.

All my code bases use that pattern and I'm the ultimate authority on what gets added or removed. My token spend is 10% to 1% of what the average in the team is and I'm the only one who knows what's happening under the hood.