Python: Promote agent-framework-declarative package to RC (#6256)

* Promote agent-framework-declarative package to RC

* Update missed package status file.

python/packages/declarative/agent_framework_declarative/__init__.py

@@ -1,5 +1,18 @@
 # Copyright (c) Microsoft. All rights reserved.
 
+"""Declarative specification support for Microsoft Agent Framework.
+
+Release stage:
+
+* The declarative-workflows surface (``WorkflowFactory``, executors, handlers,
+  etc.) is at release-candidate stability.
+* The declarative-agents surface (``AgentFactory`` and the YAML agent
+  loading/parsing path: ``DeclarativeLoaderError``, ``ProviderLookupError``,
+  ``ProviderTypeMapping``) is *experimental* and may change or be removed in
+  future versions without notice. Using these symbols emits an
+  ``ExperimentalWarning`` on first use.
+"""
+
 from importlib import metadata
 
 from ._loader import AgentFactory, DeclarativeLoaderError, ProviderLookupError, ProviderTypeMapping

python/packages/declarative/agent_framework_declarative/_loader.py

@@ -15,6 +15,10 @@ from agent_framework import (
 from agent_framework import (
     FunctionTool as AFFunctionTool,
 )
+from agent_framework._feature_stage import (  # type: ignore[reportPrivateUsage]
+    ExperimentalFeature,
+    experimental,
+)
 from agent_framework.exceptions import AgentException
 from dotenv import load_dotenv
 
@@ -43,6 +47,7 @@ else:
     from typing_extensions import TypedDict  # type: ignore # pragma: no cover
 
 
+@experimental(feature_id=ExperimentalFeature.DECLARATIVE_AGENTS)
 class ProviderTypeMapping(TypedDict, total=True):
     package: str
     name: str
@@ -118,18 +123,21 @@ PROVIDER_TYPE_OBJECT_MAPPING: dict[str, ProviderTypeMapping] = {
 }
 
 
+@experimental(feature_id=ExperimentalFeature.DECLARATIVE_AGENTS)
 class DeclarativeLoaderError(AgentException):
     """Exception raised for errors in the declarative loader."""
 
     pass
 
 
+@experimental(feature_id=ExperimentalFeature.DECLARATIVE_AGENTS)
 class ProviderLookupError(DeclarativeLoaderError):
     """Exception raised for errors in provider type lookup."""
 
     pass
 
 
+@experimental(feature_id=ExperimentalFeature.DECLARATIVE_AGENTS)
 class AgentFactory:
     """Factory for creating Agent instances from declarative YAML definitions.