diff --git a/src/strands/tools/registry.py b/src/strands/tools/registry.py
index 6bb76f560..471472a64 100644
--- a/src/strands/tools/registry.py
+++ b/src/strands/tools/registry.py
@@ -192,9 +192,9 @@ def register_tool(self, tool: AgentTool) -> None:
 
         # Check duplicate tool name, throw on duplicate tool names except if hot_reloading is enabled
         if tool.tool_name in self.registry and not tool.supports_hot_reload:
-                raise ValueError(
-                    f"Tool name '{tool.tool_name}' already exists. Cannot register tools with exact same name."
-                )
+            raise ValueError(
+                f"Tool name '{tool.tool_name}' already exists. Cannot register tools with exact same name."
+            )
 
         # Check for normalized name conflicts (- vs _)
         if self.registry.get(tool.tool_name) is None:
diff --git a/tests_integ/test_bedrock_guardrails.py b/tests_integ/test_bedrock_guardrails.py
index 4683918cb..e25bf3cca 100644
--- a/tests_integ/test_bedrock_guardrails.py
+++ b/tests_integ/test_bedrock_guardrails.py
@@ -138,9 +138,25 @@ def test_guardrail_output_intervention(boto_session, bedrock_guardrail, processi
     response1 = agent("Say the word.")
     response2 = agent("Hello!")
     assert response1.stop_reason == "guardrail_intervened"
-    assert BLOCKED_OUTPUT in str(response1)
-    assert response2.stop_reason != "guardrail_intervened"
-    assert BLOCKED_OUTPUT not in str(response2)
+
+    """
+    In async streaming: The buffering is non-blocking. 
+    Tokens are streamed while Guardrails processes the buffered content in the background. 
+    This means the response may be returned before Guardrails has finished processing.
+    As a result, we cannot guarantee that the REDACT_MESSAGE is in the response
+    """
+    if processing_mode == "sync":
+        assert BLOCKED_OUTPUT in str(response1)
+        assert response2.stop_reason != "guardrail_intervened"
+        assert BLOCKED_OUTPUT not in str(response2)
+    else:
+        cactus_returned_in_response1_blocked_by_input_guardrail = BLOCKED_INPUT in str(response2)
+        cactus_blocked_in_response1_allows_next_response = (
+            BLOCKED_OUTPUT not in str(response2) and response2.stop_reason != "guardrail_intervened"
+        )
+        assert (
+            cactus_returned_in_response1_blocked_by_input_guardrail or cactus_blocked_in_response1_allows_next_response
+        )
 
 
 @pytest.mark.parametrize("processing_mode", ["sync", "async"])
@@ -164,10 +180,27 @@ def test_guardrail_output_intervention_redact_output(bedrock_guardrail, processi
 
     response1 = agent("Say the word.")
     response2 = agent("Hello!")
+
     assert response1.stop_reason == "guardrail_intervened"
-    assert REDACT_MESSAGE in str(response1)
-    assert response2.stop_reason != "guardrail_intervened"
-    assert REDACT_MESSAGE not in str(response2)
+
+    """
+    In async streaming: The buffering is non-blocking. 
+    Tokens are streamed while Guardrails processes the buffered content in the background. 
+    This means the response may be returned before Guardrails has finished processing.
+    As a result, we cannot guarantee that the REDACT_MESSAGE is in the response
+    """
+    if processing_mode == "sync":
+        assert REDACT_MESSAGE in str(response1)
+        assert response2.stop_reason != "guardrail_intervened"
+        assert REDACT_MESSAGE not in str(response2)
+    else:
+        cactus_returned_in_response1_blocked_by_input_guardrail = BLOCKED_INPUT in str(response2)
+        cactus_blocked_in_response1_allows_next_response = (
+            REDACT_MESSAGE not in str(response2) and response2.stop_reason != "guardrail_intervened"
+        )
+        assert (
+            cactus_returned_in_response1_blocked_by_input_guardrail or cactus_blocked_in_response1_allows_next_response
+        )
 
 
 def test_guardrail_input_intervention_properly_redacts_in_session(boto_session, bedrock_guardrail, temp_dir):