> starts asking you hundreds of times "May I run sed -e blah blah blah".

In my experience, that is already a sign that it's no longer trying to do the right thing. Maybe it depends on usage patterns.

I've found that any time I have Claude refactor some code, it reaches for sed as its tool of choice. And then the builtin "sandbox" makes it ask for permission for each and every sed command, because any sed command could potentially be damaging.

Same goes for the little scripts it whips up to speed up code analysis and debugging.

And then there's the annoyance of coming back to an agent after 15 mins, only to discover that it stopped 1 minute in with a permission prompt :/