If initialize is re-sent specifying a different timeout for an SDK MCP server that's already registered, Claude Code now logs a warning that the timeout change is ignored until the server is removed and re-added, rather than silently applying or dropping the new value.
SDK MCP server timeout changes on already-registered servers are ignored with a warning
Re-sending initialize with a different timeout for a registered SDK MCP server now warns that the change is ignored.
You'll noticeTier: how much it should matter to you
2Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
MCPArea: what it touches
ImprovementsKind: in v2.1.259,
ImprovementsSection of the release