diff --git a/tests/unit/prompt_enhancer/graph/test_enhancer_node.py b/tests/unit/prompt_enhancer/graph/test_enhancer_node.py
index 5086df9..a703801 100644
--- a/tests/unit/prompt_enhancer/graph/test_enhancer_node.py
+++ b/tests/unit/prompt_enhancer/graph/test_enhancer_node.py
@@ -14,7 +14,75 @@ from src.config.report_style import ReportStyle
 def mock_llm():
     """Mock LLM that returns a test response."""
     llm = MagicMock()
-    llm.invoke.return_value = MagicMock(content="Enhanced test prompt")
+    llm.invoke.return_value = MagicMock(
+        content="""Thoughts: LLM thinks a lot
+<enhanced_prompt>
+Enhanced test prompt
+</enhanced_prompt>
+"""
+    )
+    return llm
+
+
+@pytest.fixture
+def mock_llm_xml_with_whitespace():
+    """Mock LLM that returns XML response with extra whitespace."""
+    llm = MagicMock()
+    llm.invoke.return_value = MagicMock(
+        content="""
+Some thoughts here...
+
+<enhanced_prompt>
+
+  Enhanced prompt with whitespace
+
+</enhanced_prompt>
+
+Additional content after XML
+"""
+    )
+    return llm
+
+
+@pytest.fixture
+def mock_llm_xml_multiline():
+    """Mock LLM that returns XML response with multiline content."""
+    llm = MagicMock()
+    llm.invoke.return_value = MagicMock(
+        content="""
+<enhanced_prompt>
+This is a multiline enhanced prompt
+that spans multiple lines
+and includes various formatting.
+
+It should preserve the structure.
+</enhanced_prompt>
+"""
+    )
+    return llm
+
+
+@pytest.fixture
+def mock_llm_no_xml():
+    """Mock LLM that returns response without XML tags."""
+    llm = MagicMock()
+    llm.invoke.return_value = MagicMock(
+        content="Enhanced Prompt: This is an enhanced prompt without XML tags"
+    )
+    return llm
+
+
+@pytest.fixture
+def mock_llm_malformed_xml():
+    """Mock LLM that returns response with malformed XML."""
+    llm = MagicMock()
+    llm.invoke.return_value = MagicMock(
+        content="""
+<enhanced_prompt>
+This XML tag is not properly closed
+<enhanced_prompt>
+"""
+    )
     return llm
 
 
@@ -217,3 +285,241 @@ class TestPromptEnhancerNode:
         result = prompt_enhancer_node(state)
 
         assert result == {"output": "Enhanced prompt"}
+
+    @patch("src.prompt_enhancer.graph.enhancer_node.apply_prompt_template")
+    @patch("src.prompt_enhancer.graph.enhancer_node.get_llm_by_type")
+    @patch(
+        "src.prompt_enhancer.graph.enhancer_node.AGENT_LLM_MAP",
+        {"prompt_enhancer": "basic"},
+    )
+    def test_xml_with_whitespace_handling(
+        self,
+        mock_get_llm,
+        mock_apply_template,
+        mock_llm_xml_with_whitespace,
+        mock_messages,
+    ):
+        """Test XML extraction with extra whitespace inside tags."""
+        mock_get_llm.return_value = mock_llm_xml_with_whitespace
+        mock_apply_template.return_value = mock_messages
+
+        state = PromptEnhancerState(prompt="Test prompt")
+        result = prompt_enhancer_node(state)
+
+        assert result == {"output": "Enhanced prompt with whitespace"}
+
+    @patch("src.prompt_enhancer.graph.enhancer_node.apply_prompt_template")
+    @patch("src.prompt_enhancer.graph.enhancer_node.get_llm_by_type")
+    @patch(
+        "src.prompt_enhancer.graph.enhancer_node.AGENT_LLM_MAP",
+        {"prompt_enhancer": "basic"},
+    )
+    def test_xml_multiline_content(
+        self, mock_get_llm, mock_apply_template, mock_llm_xml_multiline, mock_messages
+    ):
+        """Test XML extraction with multiline content."""
+        mock_get_llm.return_value = mock_llm_xml_multiline
+        mock_apply_template.return_value = mock_messages
+
+        state = PromptEnhancerState(prompt="Test prompt")
+        result = prompt_enhancer_node(state)
+
+        expected_output = """This is a multiline enhanced prompt
+that spans multiple lines
+and includes various formatting.
+
+It should preserve the structure."""
+        assert result == {"output": expected_output}
+
+    @patch("src.prompt_enhancer.graph.enhancer_node.apply_prompt_template")
+    @patch("src.prompt_enhancer.graph.enhancer_node.get_llm_by_type")
+    @patch(
+        "src.prompt_enhancer.graph.enhancer_node.AGENT_LLM_MAP",
+        {"prompt_enhancer": "basic"},
+    )
+    def test_fallback_to_prefix_removal(
+        self, mock_get_llm, mock_apply_template, mock_llm_no_xml, mock_messages
+    ):
+        """Test fallback to prefix removal when no XML tags are found."""
+        mock_get_llm.return_value = mock_llm_no_xml
+        mock_apply_template.return_value = mock_messages
+
+        state = PromptEnhancerState(prompt="Test prompt")
+        result = prompt_enhancer_node(state)
+
+        assert result == {"output": "This is an enhanced prompt without XML tags"}
+
+    @patch("src.prompt_enhancer.graph.enhancer_node.apply_prompt_template")
+    @patch("src.prompt_enhancer.graph.enhancer_node.get_llm_by_type")
+    @patch(
+        "src.prompt_enhancer.graph.enhancer_node.AGENT_LLM_MAP",
+        {"prompt_enhancer": "basic"},
+    )
+    def test_malformed_xml_fallback(
+        self, mock_get_llm, mock_apply_template, mock_llm_malformed_xml, mock_messages
+    ):
+        """Test handling of malformed XML tags."""
+        mock_get_llm.return_value = mock_llm_malformed_xml
+        mock_apply_template.return_value = mock_messages
+
+        state = PromptEnhancerState(prompt="Test prompt")
+        result = prompt_enhancer_node(state)
+
+        # Should fall back to using the entire content since XML is malformed
+        expected_content = """<enhanced_prompt>
+This XML tag is not properly closed
+<enhanced_prompt>"""
+        assert result == {"output": expected_content}
+
+    @patch("src.prompt_enhancer.graph.enhancer_node.apply_prompt_template")
+    @patch("src.prompt_enhancer.graph.enhancer_node.get_llm_by_type")
+    @patch(
+        "src.prompt_enhancer.graph.enhancer_node.AGENT_LLM_MAP",
+        {"prompt_enhancer": "basic"},
+    )
+    def test_case_sensitive_prefix_removal(
+        self, mock_get_llm, mock_apply_template, mock_llm, mock_messages
+    ):
+        """Test that prefix removal is case-sensitive."""
+        mock_get_llm.return_value = mock_llm
+        mock_apply_template.return_value = mock_messages
+
+        # Test case variations that should NOT be removed
+        test_cases = [
+            "ENHANCED PROMPT: This should not be removed",
+            "enhanced prompt: This should not be removed",
+            "Enhanced Prompt This should not be removed",  # Missing colon
+            "Enhanced Prompt :: This should not be removed",  # Double colon
+        ]
+
+        for response_content in test_cases:
+            mock_llm.invoke.return_value = MagicMock(content=response_content)
+
+            state = PromptEnhancerState(prompt="Test prompt")
+            result = prompt_enhancer_node(state)
+
+            # Should return the full content since prefix doesn't match exactly
+            assert result == {"output": response_content}
+
+    @patch("src.prompt_enhancer.graph.enhancer_node.apply_prompt_template")
+    @patch("src.prompt_enhancer.graph.enhancer_node.get_llm_by_type")
+    @patch(
+        "src.prompt_enhancer.graph.enhancer_node.AGENT_LLM_MAP",
+        {"prompt_enhancer": "basic"},
+    )
+    def test_prefix_with_extra_whitespace(
+        self, mock_get_llm, mock_apply_template, mock_llm, mock_messages
+    ):
+        """Test prefix removal with extra whitespace after colon."""
+        mock_get_llm.return_value = mock_llm
+        mock_apply_template.return_value = mock_messages
+
+        test_cases = [
+            ("Enhanced Prompt:   This has extra spaces", "This has extra spaces"),
+            ("Enhanced prompt:\t\tThis has tabs", "This has tabs"),
+            ("Here's the enhanced prompt:\n\nThis has newlines", "This has newlines"),
+        ]
+
+        for response_content, expected_output in test_cases:
+            mock_llm.invoke.return_value = MagicMock(content=response_content)
+
+            state = PromptEnhancerState(prompt="Test prompt")
+            result = prompt_enhancer_node(state)
+
+            assert result == {"output": expected_output}
+
+    @patch("src.prompt_enhancer.graph.enhancer_node.apply_prompt_template")
+    @patch("src.prompt_enhancer.graph.enhancer_node.get_llm_by_type")
+    @patch(
+        "src.prompt_enhancer.graph.enhancer_node.AGENT_LLM_MAP",
+        {"prompt_enhancer": "basic"},
+    )
+    def test_xml_with_special_characters(
+        self, mock_get_llm, mock_apply_template, mock_llm, mock_messages
+    ):
+        """Test XML extraction with special characters and symbols."""
+        mock_get_llm.return_value = mock_llm
+        mock_apply_template.return_value = mock_messages
+
+        special_content = """<enhanced_prompt>
+Enhanced prompt with special chars: @#$%^&*()
+Unicode: 🚀 ✨ 💡
+Quotes: "double" and 'single'
+Backslashes: \\n \\t \\r
+</enhanced_prompt>"""
+
+        mock_llm.invoke.return_value = MagicMock(content=special_content)
+
+        state = PromptEnhancerState(prompt="Test prompt")
+        result = prompt_enhancer_node(state)
+
+        expected_output = """Enhanced prompt with special chars: @#$%^&*()
+Unicode: 🚀 ✨ 💡
+Quotes: "double" and 'single'
+Backslashes: \\n \\t \\r"""
+        assert result == {"output": expected_output}
+
+    @patch("src.prompt_enhancer.graph.enhancer_node.apply_prompt_template")
+    @patch("src.prompt_enhancer.graph.enhancer_node.get_llm_by_type")
+    @patch(
+        "src.prompt_enhancer.graph.enhancer_node.AGENT_LLM_MAP",
+        {"prompt_enhancer": "basic"},
+    )
+    def test_very_long_response(
+        self, mock_get_llm, mock_apply_template, mock_llm, mock_messages
+    ):
+        """Test handling of very long LLM responses."""
+        mock_get_llm.return_value = mock_llm
+        mock_apply_template.return_value = mock_messages
+
+        # Create a very long response
+        long_content = "This is a very long enhanced prompt. " * 100
+        xml_response = f"<enhanced_prompt>\n{long_content}\n</enhanced_prompt>"
+
+        mock_llm.invoke.return_value = MagicMock(content=xml_response)
+
+        state = PromptEnhancerState(prompt="Test prompt")
+        result = prompt_enhancer_node(state)
+
+        assert result == {"output": long_content.strip()}
+        assert len(result["output"]) > 1000  # Verify it's actually long
+
+    @patch("src.prompt_enhancer.graph.enhancer_node.apply_prompt_template")
+    @patch("src.prompt_enhancer.graph.enhancer_node.get_llm_by_type")
+    @patch(
+        "src.prompt_enhancer.graph.enhancer_node.AGENT_LLM_MAP",
+        {"prompt_enhancer": "basic"},
+    )
+    def test_empty_response_content(
+        self, mock_get_llm, mock_apply_template, mock_llm, mock_messages
+    ):
+        """Test handling of empty response content."""
+        mock_get_llm.return_value = mock_llm
+        mock_apply_template.return_value = mock_messages
+
+        mock_llm.invoke.return_value = MagicMock(content="")
+
+        state = PromptEnhancerState(prompt="Test prompt")
+        result = prompt_enhancer_node(state)
+
+        assert result == {"output": ""}
+
+    @patch("src.prompt_enhancer.graph.enhancer_node.apply_prompt_template")
+    @patch("src.prompt_enhancer.graph.enhancer_node.get_llm_by_type")
+    @patch(
+        "src.prompt_enhancer.graph.enhancer_node.AGENT_LLM_MAP",
+        {"prompt_enhancer": "basic"},
+    )
+    def test_only_whitespace_response(
+        self, mock_get_llm, mock_apply_template, mock_llm, mock_messages
+    ):
+        """Test handling of response with only whitespace."""
+        mock_get_llm.return_value = mock_llm
+        mock_apply_template.return_value = mock_messages
+
+        mock_llm.invoke.return_value = MagicMock(content="   \n\n\t\t   ")
+
+        state = PromptEnhancerState(prompt="Test prompt")
+        result = prompt_enhancer_node(state)
+
+        assert result == {"output": ""}