Relevant spec: - [Scope Selection Strategy](https://modelcontextprotocol.io/specification/2025-11-25/basic/authorization#scope-selection-strategy) - [Scope Challenge Handling](https://modelcontextprotocol.io/specification/2025-11-25/basic/authorization#scope-challenge-handling) See also: https://github.com/modelcontextprotocol/modelcontextprotocol/pull/835
