You'll noticeTier: how much it should matter to you
2Useful: my rating, 1 to 5
2Signal: worth watching, 1 to 5
MessagesArea: what it touches
ImprovementsKind: in v2.1.301,
ImprovementsSection of the release
What
A tool call is a single action Claude takes, such as reading a file or running a command. A turn is one round of Claude's work before it hands control back to you. Claude Code now sends Claude two new messages for unusual situations:
A turn that did not end: Claude asked to end its turn, but another tool call in the same message failed. Claude is told the turn did not end and that it should deal with the failure first.
An oversized MCP result: MCP (Model Context Protocol) lets Claude Code use tools from outside servers. When such a call's result was meant to be kept from Claude and was too large, Claude is told the result went over the size limit and nothing came back.
Why
In both cases Claude now gets a plain explanation instead of being left to guess. It should handle a failed action before stopping, and it should not assume a large MCP result arrived.