Under the hoodTier: how much it should matter to you
2Useful: my rating, 1 to 5
3Signal: worth watching, 1 to 5
PluginsArea: what it touches
Internal ChangesKind: in v2.1.302,
Internal ChangesSection of the release
What
An MCP server is an add-on program that gives Claude extra tools. A built-in plugin, one that ships with Claude Code, can now refuse calls to an MCP server it provides. When it does, the call fails with a message saying the server was not called because the plugin that provides it refused this call.
If the plugin's own check fails with an error, the server is refused too.
Why
Built-in plugins can switch off their own MCP servers. If you see this message, the plugin that provides the server blocked the call, not your settings.
