{"version":"2.1.224","anchor":"mcp-connection-failures-report-a-sibling-probe-result","canonical_anchor":"mcp-connection-failures-report-a-sibling-probe-result","heading":"MCP connection failures report a sibling probe result","tier":"internal","area":"MCP","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.224\/e\/mcp-connection-failures-report-a-sibling-probe-result","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.224","markdown":"### MCP connection failures report a sibling probe result\n\nFailed MCP connections now report an extra probe result for easier diagnosis.\n\n**What**\n\nThe telemetry event for a failed MCP server connection carries one more field describing the probe, giving more detail when a server will not connect.\n\n**Details**\n\n- `probeSibling` joins the existing `negotiationMode`, `probeFellBack`, `errorCode` and `errorClassName` fields.\n- The field name does not appear in the previous build.\n\n**Evidence**\n\n`probeSibling`\n\n- Area: MCP\n- Tier: Under the hood\n- Useful: 2\/5\n- Signal: 2\/5"}