diff --git a/python/packages/foundry/agent_framework_foundry/_agent.py b/python/packages/foundry/agent_framework_foundry/_agent.py
index 0c7f93ba1f..626881b3ac 100644
--- a/python/packages/foundry/agent_framework_foundry/_agent.py
+++ b/python/packages/foundry/agent_framework_foundry/_agent.py
@@ -34,7 +34,7 @@
 from azure.core.credentials import TokenCredential
 from azure.core.credentials_async import AsyncTokenCredential
 
-from ._tools import sanitize_foundry_response_tool
+from ._tools import _sanitize_foundry_response_tool  # pyright: ignore[reportPrivateUsage]
 
 if sys.version_info >= (3, 13):
     from typing import TypeVar  # type: ignore # pragma: no cover
@@ -321,7 +321,7 @@ def _prepare_tools_for_openai(
         surface.
         """
         response_tools = super()._prepare_tools_for_openai(tools)
-        return [sanitize_foundry_response_tool(tool_item) for tool_item in response_tools]
+        return [_sanitize_foundry_response_tool(tool_item) for tool_item in response_tools]
 
     def _prepare_messages_for_azure_ai(self, messages: Sequence[Message]) -> tuple[list[Message], str | None]:
         """Extract system/developer messages as instructions for Azure AI.
diff --git a/python/packages/foundry/agent_framework_foundry/_chat_client.py b/python/packages/foundry/agent_framework_foundry/_chat_client.py
index 735ba9fb57..353268a129 100644
--- a/python/packages/foundry/agent_framework_foundry/_chat_client.py
+++ b/python/packages/foundry/agent_framework_foundry/_chat_client.py
@@ -33,7 +33,7 @@
 from azure.core.credentials import TokenCredential
 from azure.core.credentials_async import AsyncTokenCredential
 
-from ._tools import fetch_toolbox, sanitize_foundry_response_tool
+from ._tools import _sanitize_foundry_response_tool, fetch_toolbox  # pyright: ignore[reportPrivateUsage]
 
 if sys.version_info >= (3, 13):
     from typing import TypeVar  # type: ignore # pragma: no cover
@@ -235,7 +235,7 @@ def _prepare_tools_for_openai(
         them downstream.
         """
         response_tools = super()._prepare_tools_for_openai(tools)
-        return [sanitize_foundry_response_tool(tool_item) for tool_item in response_tools]
+        return [_sanitize_foundry_response_tool(tool_item) for tool_item in response_tools]
 
     async def configure_azure_monitor(
         self,
diff --git a/python/packages/foundry/agent_framework_foundry/_tools.py b/python/packages/foundry/agent_framework_foundry/_tools.py
index 4c5956fcfe..40b8bf0905 100644
--- a/python/packages/foundry/agent_framework_foundry/_tools.py
+++ b/python/packages/foundry/agent_framework_foundry/_tools.py
@@ -155,8 +155,7 @@ def _validate_hosted_tool_payload(sanitized: Mapping[str, Any]) -> None:
         )
 
 
-@experimental(feature_id=ExperimentalFeature.TOOLBOXES)
-def sanitize_foundry_response_tool(tool_item: Any) -> Any:
+def _sanitize_foundry_response_tool(tool_item: Any) -> Any:  # pyright: ignore[reportUnusedFunction]
     """Return a Responses-API-safe tool payload for Foundry hosted tools.
 
     Reconciles known mismatches between toolbox reads and the Responses API: