{"version":"2.1.323","anchor":"mcp-task-augmented-tool-call-cancelled-if-follow-token-can","canonical_anchor":"mcp-task-augmented-tool-call-cancelled-if-follow-token-can","heading":"MCP background tasks are cancelled when their follow-up data is too large","tier":"notice","area":"MCP","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.323\/e\/mcp-task-augmented-tool-call-cancelled-if-follow-token-can","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.323","markdown":"### MCP background tasks are cancelled when their follow-up data is too large\n\nAn MCP tool call that starts a background task now fails and cancels the task if its follow-up data is too large or too nested\n\n**What**\n\nMCP servers are add-ons that give Claude extra tools, and some of their tools start a task that keeps running in the background. If the data Claude Code needs to keep following that task is too large or too deeply nested to pass on, the call now fails with an error saying the task is being cancelled and nothing more of it will arrive.\n\n**Why**\n\nThis is a new way an MCP background task can end: instead of continuing out of reach, it is stopped and the call reports an error.\n\n- Area: MCP\n- Tier: You'll notice\n- Useful: 1\/5\n- Signal: 1\/5\n- Scope: individual\n- Heads-up: no"}