diff --git a/python/packages/core/agent_framework/_harness/_tool_approval.py b/python/packages/core/agent_framework/_harness/_tool_approval.py
index 7c6df089c9d..2232093ea3f 100644
--- a/python/packages/core/agent_framework/_harness/_tool_approval.py
+++ b/python/packages/core/agent_framework/_harness/_tool_approval.py
@@ -130,10 +130,9 @@ def __init__(
             server_label: Optional hosted-tool server boundary. Hosted approvals
                 only match future approvals from the same server label.
         """
-        normalized_name = tool_name.strip()
-        if not normalized_name:
+        if not tool_name.strip():
             raise ValueError("Tool approval rule tool_name must be a non-empty string.")
-        self.tool_name = normalized_name
+        self.tool_name = tool_name
         self.arguments = dict(arguments) if arguments is not None else None
         self.server_label = server_label
 
diff --git a/python/packages/core/tests/core/test_harness_tool_approval.py b/python/packages/core/tests/core/test_harness_tool_approval.py
index 24db9cad0b5..a0d1c54bfa0 100644
--- a/python/packages/core/tests/core/test_harness_tool_approval.py
+++ b/python/packages/core/tests/core/test_harness_tool_approval.py
@@ -37,6 +37,7 @@
     SessionContext,
     SupportsAgentRun,
     ToolApprovalMiddleware,
+    ToolApprovalRule,
     ToolApprovalState,
     create_always_approve_tool_response,
     create_always_approve_tool_with_arguments_response,
@@ -66,6 +67,14 @@ def _function_call(request: Content) -> Content:
     return request.function_call
 
 
+def test_tool_approval_rule_preserves_tool_name_whitespace() -> None:
+    """Tool approval rules must preserve the exact approved tool identity."""
+    rule = ToolApprovalRule("run_shell ")
+
+    assert rule.tool_name == "run_shell "
+    assert ToolApprovalRule.from_dict(rule.to_dict()).tool_name == "run_shell "
+
+
 class _MarkUntrusted(FunctionMiddleware):
     async def process(
         self,