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Sweep 22 Oct 2026 · 21:04Z Build v2.1.309 528 read Stable v2.1.308 Latest v2.1.309 Next v2.1.309 Feeds RSS JSON llms.txt llms-full.txt Unofficial

Claude Code v2.1.309 ·

Oversized MCP tool results without text now produce a clear error

An MCP tool result that arrives without its text now raises an error telling Claude the tool may already have run

You'll notice Improvements
JSON All of v2.1.309
You'll noticeTier: how much it should matter to you
2Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
MCPArea: what it touches
ImprovementsKind: in v2.1.309,
ImprovementsSection of the release
What

MCP (Model Context Protocol) tools are outside tools that Claude Code connects to. Sometimes a result is too large and arrives marked as having left its text out. When that happens and there is no text in it, Claude Code no longer passes the result on. It reports an error to Claude instead. The error explains three things:

  • that a result this large arrives this way
  • that the tool may already have run
  • that Claude should check before running it again, and ask for less data
Why

This keeps Claude from quietly running a tool a second time when the first run may already have changed something.

See this entry in the whole of v2.1.309 →

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