diff --git a/tests/unittests/tools/mcp_tool/test_conversion_utils.py b/tests/unittests/tools/mcp_tool/test_conversion_utils.py
new file mode 100644
index 000000000..c43f65dd4
--- /dev/null
+++ b/tests/unittests/tools/mcp_tool/test_conversion_utils.py
@@ -0,0 +1,106 @@
+from typing import Any, Dict
+from unittest.mock import MagicMock
+
+import pytest
+from google.genai.types import Schema, Type
+
+from src.google.adk.tools.mcp_tool.conversion_utils import (
+    adk_to_mcp_tool_type,
+    gemini_to_json_schema,
+)
+from src.google.adk.tools.base_tool import BaseTool
+import mcp.types as mcp_types
+
+
+def test_adk_to_mcp_tool_type():
+    """Test adk_to_mcp_tool_type with a mock BaseTool."""
+    mock_tool = MagicMock(spec=BaseTool)
+    mock_tool.name = "test_tool"
+    mock_tool.description = "test_description"
+    mock_tool._get_declaration.return_value = None
+
+    mcp_tool = adk_to_mcp_tool_type(mock_tool)
+
+    assert isinstance(mcp_tool, mcp_types.Tool)
+    assert mcp_tool.name == "test_tool"
+    assert mcp_tool.description == "test_description"
+    assert mcp_tool.inputSchema == {}
+
+    mock_declaration = MagicMock()
+    mock_declaration.parameters = Schema(type=Type.STRING)
+    mock_tool._get_declaration.return_value = mock_declaration
+    mcp_tool = adk_to_mcp_tool_type(mock_tool)
+    assert mcp_tool.inputSchema == {"type": "string"}
+
+
+def test_gemini_to_json_schema_string():
+    """Test gemini_to_json_schema with a STRING schema."""
+    gemini_schema = Schema(type=Type.STRING, title="test_string", description="test string description", default="test", enum=["a", "b"], format="test_format", example="example", pattern="test_pattern", min_length=1, max_length=10)
+    json_schema = gemini_to_json_schema(gemini_schema)
+    assert json_schema == {
+        "type": "string",
+        "title": "test_string",
+        "description": "test string description",
+        "default": "test",
+        "enum": ["a", "b"],
+        "format": "test_format",
+        "example": "example",
+        "pattern": "test_pattern",
+        "minLength": 1,
+        "maxLength": 10,
+    }
+
+
+def test_gemini_to_json_schema_number():
+    """Test gemini_to_json_schema with a NUMBER schema."""
+    gemini_schema = Schema(type=Type.NUMBER, minimum=1.0, maximum=10.0)
+    json_schema = gemini_to_json_schema(gemini_schema)
+    assert json_schema == {"type": "number", "minimum": 1.0, "maximum": 10.0}
+
+
+def test_gemini_to_json_schema_integer():
+    """Test gemini_to_json_schema with an INTEGER schema."""
+    gemini_schema = Schema(type=Type.INTEGER, minimum=1, maximum=10)
+    json_schema = gemini_to_json_schema(gemini_schema)
+    assert json_schema == {"type": "integer", "minimum": 1, "maximum": 10}
+
+
+def test_gemini_to_json_schema_array():
+    """Test gemini_to_json_schema with an ARRAY schema."""
+    gemini_schema = Schema(type=Type.ARRAY, items=Schema(type=Type.STRING), min_items=1, max_items=10)
+    json_schema = gemini_to_json_schema(gemini_schema)
+    assert json_schema == {"type": "array", "items": {"type": "string"}, "minItems": 1, "maxItems": 10}
+
+
+def test_gemini_to_json_schema_object():
+    """Test gemini_to_json_schema with an OBJECT schema."""
+    gemini_schema = Schema(type=Type.OBJECT, properties={"prop1": Schema(type=Type.STRING)}, required=["prop1"], min_properties=1, max_properties=10)
+    json_schema = gemini_to_json_schema(gemini_schema)
+    assert json_schema == {"type": "object", "properties": {"prop1": {"type": "string"}}, "required": ["prop1"], "minProperties": 1, "maxProperties": 10}
+
+
+def test_gemini_to_json_schema_nullable():
+    """Test gemini_to_json_schema with a nullable schema."""
+    gemini_schema = Schema(type=Type.STRING, nullable=True)
+    json_schema = gemini_to_json_schema(gemini_schema)
+    assert json_schema == {"type": "string", "nullable": True}
+
+
+def test_gemini_to_json_schema_any_of():
+    """Test gemini_to_json_schema with an anyOf schema."""
+    gemini_schema = Schema(type=Type.OBJECT, any_of=[Schema(type=Type.STRING), Schema(type=Type.INTEGER)])
+    json_schema = gemini_to_json_schema(gemini_schema)
+    assert json_schema == {"type": "object", "anyOf": [{"type": "string"}, {"type": "integer"}]}
+
+
+def test_gemini_to_json_schema_type_error():
+    """Test gemini_to_json_schema raises TypeError when input is not a Schema."""
+    with pytest.raises(TypeError):
+        gemini_to_json_schema("not a schema") 
+
+
+def test_gemini_to_json_schema_unspecified_type():
+    """Test gemini_to_json_schema with an unspecified type."""
+    gemini_schema = Schema()
+    json_schema = gemini_to_json_schema(gemini_schema)
+    assert json_schema == {"type": "null"}
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