Stdio MCP servers that exit right after a startup probe times out now get one automatic restart
When Claude Code connects to an MCP server over stdio (standard input/output, used for local server processes), it sometimes runs a version-negotiation probe first. If that probe times out and the server process then closes while still initializing, Claude Code now recognizes this specific pattern - a likely slow-starting server that exits on requests sent before it's ready - and restarts the server once without the probe, using whatever time is left in the connection budget.
Previously, only a different failure (a version-negotiation error causing the connection to close) triggered a stdio server restart; a probe-timeout-induced close was not handled.
This reduces false failures for MCP servers that are simply slow to start up, giving them a second chance to connect properly instead of failing outright.