You may be running into a "known" bug with Claude Code: https://github.com/anthropics/claude-code/issues/63930

This happens all the time and drives me bananas.

It seems to be regular file edits rather than parallel tool calls.

I'm sitting on 1.6m cache write even now with 468k in /context. It drives my session costs above $100 regularly.

Can someone from Anthropic look into this?