You'll notice
Adding or replacing a hook now runs a validation check before applying the change
What
Hooks are scripts that run automatically at certain points, such as before or after a tool call. When you add or replace a hook matcher (the rule that decides when a hook fires), Claude Code now runs a validation pass first. If that validation fails, the operation is rejected with a specific outcome instead of always being applied.
Why
This stops invalid hook configurations from being silently saved, catching problems at the point of change rather than later when the hook fails to work as expected.