You'll noticeTier: how much it should matter to you
1Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
Bash ToolArea: what it touches
ImprovementsKind: in v2.1.300,
ImprovementsSection of the release
What
The Bash tool is how Claude runs commands on your computer, and Claude reads a description of how to use it. That description was rewritten in this release, as measured on the prompt the running client sends:
Main prompt: changed for the interactive Claude Code prompt, with and without an account, across 13 captured model setups. Another set of model setups got a different edit. The new text includes: 'Foreground sleep is blocked; use Monitor with an until-loop to wait on a condition.'
Agent prompt: changed in the agent-claude prompt. The new text includes: 'You will be notified when it exits - do not poll its output file while waiting.'
The longest version of the description captured under this release is 9,857 characters.
Why
These are Claude's own instructions, so changes here can change how Claude runs commands, particularly when it waits for something or runs a command in the background. What the change does in practice is a reading of the text, not something measured.
