Claude Code 2.1.306 stops MCP-heavy sessions misreporting API errors as "prompt is too long"
The Oct 21 release fixes sessions with many MCP tools showing a real API error as "prompt is too long" and running an unneeded compaction; per TurboAI, a 400 or 422 that names deferred tools now retries without them. It also fixes claude -p inside cloud sessions reporting "Not logged in" when started without the session's environment variables.
