diff --git a/ra_aid/agent_utils.py b/ra_aid/agent_utils.py
index 26e4f50..565d6a9 100644
--- a/ra_aid/agent_utils.py
+++ b/ra_aid/agent_utils.py
@@ -933,7 +933,6 @@ def run_agent_with_retry(
                             original_prompt, config, test_attempts, auto_test
                         )
                     )
-                    cpm(f"res:{should_break, prompt, auto_test, test_attempts}")
                     if should_break:
                         break
                     if prompt != original_prompt:
diff --git a/ra_aid/fallback_handler.py b/ra_aid/fallback_handler.py
index 3b7bac0..c2cf07f 100644
--- a/ra_aid/fallback_handler.py
+++ b/ra_aid/fallback_handler.py
@@ -157,10 +157,16 @@ class FallbackHandler:
         for fallback_model in self.fallback_tool_models:
             result_list = self.invoke_fallback(fallback_model)
             if result_list:
-                # msg_list_response = [SystemMessage(str(msg)) for msg in result_list]
                 return result_list
-        cpm("All fallback models have failed", title="Fallback Failed")
-        return None
+
+        cpm("All fallback models have failed.", title="Fallback Failed")
+
+        current_failing_tool_name = self.current_failing_tool_name
+        self.reset_fallback_handler()
+
+        raise FallbackToolExecutionError(
+            f"All fallback models have failed for tool: {current_failing_tool_name}"
+        )
 
     def reset_fallback_handler(self):
         """
diff --git a/tests/ra_aid/test_fallback_handler.py b/tests/ra_aid/test_fallback_handler.py
index c400a19..3a2edcf 100644
--- a/tests/ra_aid/test_fallback_handler.py
+++ b/tests/ra_aid/test_fallback_handler.py
@@ -22,16 +22,17 @@ class TestFallbackHandler(unittest.TestCase):
         self.config = {
             "max_tool_failures": 2,
             "fallback_tool_models": "dummy-fallback-model",
+            "experimental_fallback_handler": True,
         }
-        self.fallback_handler = FallbackHandler(self.config)
+        self.fallback_handler = FallbackHandler(self.config, [])
         self.logger = DummyLogger()
         self.agent = DummyAgent()
 
     def test_handle_failure_increments_counter(self):
+        from ra_aid.exceptions import ToolExecutionError
         initial_failures = self.fallback_handler.tool_failure_consecutive_failures
-        self.fallback_handler.handle_failure(
-            "dummy_call()", Exception("Test error"), self.logger, self.agent
-        )
+        error_obj = ToolExecutionError("Test error", base_message="dummy_call()", tool_name="dummy_tool")
+        self.fallback_handler.handle_failure(error_obj, self.agent)
         self.assertEqual(
             self.fallback_handler.tool_failure_consecutive_failures,
             initial_failures + 1,
@@ -62,9 +63,7 @@ class TestFallbackHandler(unittest.TestCase):
         llm.validate_provider_env = dummy_validate_provider_env
 
         self.fallback_handler.tool_failure_consecutive_failures = 2
-        self.fallback_handler.attempt_fallback(
-            "dummy_tool_call()", self.logger, self.agent
-        )
+        self.fallback_handler.attempt_fallback()
         self.assertEqual(self.fallback_handler.tool_failure_consecutive_failures, 0)
 
         llm.initialize_llm = original_initialize
diff --git a/tests/ra_aid/test_llm.py b/tests/ra_aid/test_llm.py
index 6789132..7f96ed4 100644
--- a/tests/ra_aid/test_llm.py
+++ b/tests/ra_aid/test_llm.py
@@ -121,7 +121,7 @@ def test_initialize_expert_openai_compatible(clean_env, mock_openai, monkeypatch
 
 def test_initialize_expert_unsupported_provider(clean_env):
     """Test error handling for unsupported provider in expert mode."""
-    with pytest.raises(ValueError, match=r"Unsupported provider: unknown"):
+    with pytest.raises(ValueError, match=r"Missing required environment variable for provider: unknown"):
         initialize_expert_llm("unknown", "model")
 
 
@@ -197,7 +197,7 @@ def test_initialize_unsupported_provider(clean_env):
     """Test initialization with unsupported provider raises ValueError"""
     with pytest.raises(ValueError) as exc_info:
         initialize_llm("unsupported", "model")
-    assert str(exc_info.value) == "Unsupported provider: unsupported"
+    assert str(exc_info.value) == "Missing required environment variable for provider: unsupported"
 
 
 def test_temperature_defaults(clean_env, mock_openai, mock_anthropic, mock_gemini):