Claude Code now waits briefly for SDK-configured MCP servers to finish connecting before starting the first turn
What
When a session is configured with SDK MCP servers (external tool servers set up through the SDK), the first query of a turn now waits for any of those servers that are still connecting, instead of immediately proceeding without their tools. A new tracker keeps a list of configured-but-not-yet-connected servers and the turn logic waits on it before continuing.
The wait is bounded by the existing MCP connect timeout (default 5 seconds). Claude Code logs whether the wait timed out and which servers were still pending. If a server still hasn't connected once the wait ends, the turn proceeds without that server's tools and a warning is shown.
Why
Previously a turn could start before slow-to-connect MCP servers were ready, silently missing their tools for that turn. This change gives those servers a short grace period to finish connecting, reducing the chance that a tool is unexpectedly unavailable just because it hadn't connected yet.