{"version":"2.1.309","anchor":"mcp-tool-results-that-arrive-without-text-blocks-now-throw-a","canonical_anchor":"mcp-tool-results-that-arrive-without-text-blocks-now-throw-a","heading":"Oversized MCP tool results without text now produce a clear error","tier":"notice","area":"MCP","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.309\/e\/mcp-tool-results-that-arrive-without-text-blocks-now-throw-a","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.309","markdown":"### Oversized MCP tool results without text now produce a clear error\n\nAn MCP tool result that arrives without its text now raises an error telling Claude the tool may already have run\n\n**What**\n\nMCP (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:\n\n- that a result this large arrives this way\n\n- that the tool may already have run\n\n- that Claude should check before running it again, and ask for less data\n\n**Why**\n\nThis keeps Claude from quietly running a tool a second time when the first run may already have changed something.\n\n- Area: MCP\n- Tier: You'll notice\n- Useful: 2\/5\n- Signal: 1\/5\n- Scope: individual\n- Heads-up: no"}