{"version":"2.1.311","anchor":"new-error-for-mcp-structured-content-that-cannot-be-read","canonical_anchor":"new-error-for-mcp-structured-content-that-cannot-be-read","heading":"Clearer error when an MCP tool's structured result cannot be read","tier":"notice","area":"MCP","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.311\/e\/new-error-for-mcp-structured-content-that-cannot-be-read","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.311","markdown":"### Clearer error when an MCP tool's structured result cannot be read\n\nWhen an MCP tool's structured result cannot be read, Claude is told why and warned the tool may already have run\n\n**What**\n\nMCP 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.\n\n**Why**\n\nClaude gets a clear explanation instead of a generic failure, and is warned against simply retrying a tool that may already have done its work.\n\n- Area: MCP\n- Tier: You'll notice\n- Useful: 1\/5\n- Signal: 1\/5\n- Scope: individual\n- Heads-up: no"}