Python: propagate as_tool() kwargs. Add sample for runtime context with as_tool kwargs and middleware. (#2311)

* as tool kwargs

* simplify

python/samples/README.md

@@ -206,6 +206,7 @@ This directory contains samples demonstrating the capabilities of Microsoft Agen
 | [`getting_started/middleware/function_based_middleware.py`](./getting_started/middleware/function_based_middleware.py) | Function-based middleware example |
 | [`getting_started/middleware/middleware_termination.py`](./getting_started/middleware/middleware_termination.py) | Middleware termination example |
 | [`getting_started/middleware/override_result_with_middleware.py`](./getting_started/middleware/override_result_with_middleware.py) | Override result with middleware example |
+| [`getting_started/middleware/runtime_context_delegation.py`](./getting_started/middleware/runtime_context_delegation.py) | Runtime context delegation example demonstrating how to pass API tokens, session data, and other context through hierarchical agent delegation |
 | [`getting_started/middleware/shared_state_middleware.py`](./getting_started/middleware/shared_state_middleware.py) | Shared state middleware example |
 | [`getting_started/middleware/thread_behavior_middleware.py`](./getting_started/middleware/thread_behavior_middleware.py) | Thread behavior middleware example demonstrating how to track conversation state across multiple agent runs |