high95%
stdio sessions hang forever when a server never responds (no default read_timeout_seconds)
langchain_mcp_adapters.sessions._create_stdio_session constructs an MCP ClientSession without a default read_timeout_seconds, so any request to a non-responsive stdio server (e.g., during initialize()/call_tool()/list_tools()) blocks indefinitely. The MCP SDK already supports per-request timeouts via read_timeout_seconds; this library simply fails to set a default.