{"version":"2.1.302","anchor":"mcp-modern-protocol-connections-tolerate-results-missing-req","canonical_anchor":"mcp-modern-protocol-connections-tolerate-results-missing-req","heading":"MCP servers that leave out required result fields can now connect","tier":"notice","area":"MCP","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.302\/e\/mcp-modern-protocol-connections-tolerate-results-missing-req","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.302","markdown":"### MCP servers that leave out required result fields can now connect\n\nWith automatic protocol negotiation, Claude Code fills in missing required fields on MCP results instead of rejecting them\n\n**What**\n\nMCP (Model Context Protocol) is the standard Claude Code uses to connect to outside servers that give Claude extra tools. When Claude Code works out the protocol version with a server automatically, these things are different:\n\n- If a server's result leaves out the required fields `resultType`, `ttlMs` or `cacheScope`, Claude Code fills them in instead of rejecting the result, and logs this once per kind of request.\n\n- A web request to a server can be sent again once, after a check approves the retry.\n\n- Reconnecting to a long-running MCP task has a new option to take a single quick look, without redialing the stored connection or waiting.\n\n**Why**\n\nServers that speak the 2026-07-28 version of the protocol but leave out required fields should now connect instead of failing.\n\n- Area: MCP\n- Tier: You'll notice\n- Useful: 2\/5\n- Signal: 1\/5\n- Scope: individual\n- Heads-up: no"}