Troubleshoot Mcp Connection

Diagnose and fix MCP server connection issues between Claude Code, Claude Desktop, and MCP servers. Covers Windows argument parsing, authentication failures, transport issues, and platform-specific debugging. Use when Claude Code or Claude Desktop fails to connect to an MCP server, when MCP tools don't appear in sessions, on "cannot attach the server" errors, when a working connection has stopped, or when setting up MCP on a new machine.