{"version":"2.1.232","anchor":"mcp-legacy-fallback-records-which-probe-failure-caused-it","canonical_anchor":"mcp-legacy-fallback-records-which-probe-failure-caused-it","heading":"MCP legacy fallback records which probe failure caused it","tier":"internal","area":"MCP","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.232\/e\/mcp-legacy-fallback-records-which-probe-failure-caused-it","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.232","markdown":"### MCP legacy fallback records which probe failure caused it\n\nWhen an MCP server falls back to the older transport, the exact reason is now recorded.\n\n**What**\n\nWhen probing an MCP server falls back to the legacy transport, the reason is now recorded distinctly as an id mismatch, a malformed response or a premature stream end, rather than one undifferentiated legacy fallback.\n\n**Evidence**\n\n`_anthropicProbeLegacyEvidence`\n\n- Area: MCP\n- Tier: Under the hood\n- Useful: 2\/5\n- Signal: 2\/5"}