You'll noticeTier: how much it should matter to you
1Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
MCPArea: what it touches
ImprovementsKind: in v2.1.311,
ImprovementsSection of the release
What
MCP servers are add-ons that give Claude extra tools. Some tools return structured content, meaning data in a fixed format rather than plain text. When Claude Code cannot read that content, it now reports a specific error saying the content may be too large, nested too deeply, or contain a number that is too large. The error also says the tool may have run anyway, so Claude should check before calling it again.
Why
Claude gets a clear explanation instead of a generic failure, and is warned against simply retrying a tool that may already have done its work.
