Unclear The finding does not say which consumers receive this reduced payload, including whether user-configured hooks do.
What
Every time Claude uses a tool, Claude Code produces a tool.call event describing that tool call. Before this event is handed on, the step that prepares it now deletes one field, isReadOnly, which says whether the call only reads things.
Why
Anything that received tool.call events and looked at isReadOnly will no longer find it there.
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt
The finding does not say which consumers receive this reduced payload, including whether user-configured hooks do.