diff --git a/workflowai/core/utils/_tools.py b/workflowai/core/utils/_tools.py
index f16632e..d0d4184 100644
--- a/workflowai/core/utils/_tools.py
+++ b/workflowai/core/utils/_tools.py
@@ -1,8 +1,8 @@
+import contextlib
 import inspect
-from enum import Enum
-from typing import Any, Callable, NamedTuple, Optional, cast, get_type_hints
+from typing import Any, Callable, NamedTuple, Optional, get_type_hints
 
-from pydantic import BaseModel
+from pydantic import TypeAdapter
 
 from workflowai.core.utils._schema_generator import JsonSchemaGenerator
 
@@ -24,10 +24,6 @@ def _get_type_schema(param_type: type):
     Returns:
         A dictionary containing the JSON schema type definition
     """
-    if issubclass(param_type, Enum):
-        if not issubclass(param_type, str):
-            raise ValueError(f"Non string enums are not supported: {param_type}")
-        return SchemaDeserializer({"type": "string", "enum": [e.value for e in param_type]})
 
     if param_type is str:
         return SchemaDeserializer({"type": "string"})
@@ -41,11 +37,13 @@ def _get_type_schema(param_type: type):
     if param_type is bool:
         return SchemaDeserializer({"type": "boolean"})
 
-    if issubclass(param_type, BaseModel):
+    # Attempting to build a type adapter with pydantic
+    with contextlib.suppress(Exception):
+        adapter = TypeAdapter[Any](param_type)
         return SchemaDeserializer(
-            schema=param_type.model_json_schema(by_alias=True, schema_generator=JsonSchemaGenerator),
-            serializer=lambda x: cast(BaseModel, x).model_dump(mode="json"),  # pyright: ignore [reportUnknownLambdaType]
-            deserializer=param_type.model_validate,
+            schema=adapter.json_schema(schema_generator=JsonSchemaGenerator),
+            deserializer=adapter.validate_python,  # pyright: ignore [reportUnknownLambdaType]
+            serializer=lambda x: adapter.dump_python(x, mode="json"),  # pyright: ignore [reportUnknownLambdaType]
         )
 
     raise ValueError(f"Unsupported type: {param_type}")
diff --git a/workflowai/core/utils/_tools_test.py b/workflowai/core/utils/_tools_test.py
index d6c04da..2825374 100644
--- a/workflowai/core/utils/_tools_test.py
+++ b/workflowai/core/utils/_tools_test.py
@@ -1,9 +1,54 @@
+import json
+from datetime import datetime
 from enum import Enum
-from typing import Annotated
+from typing import Annotated, Any
 
+import pytest
 from pydantic import BaseModel
-
-from workflowai.core.utils._tools import tool_schema
+from zoneinfo import ZoneInfo
+
+from workflowai.core.utils._tools import _get_type_schema, tool_schema  # pyright: ignore [reportPrivateUsage]
+
+
+class TestGetTypeSchema:
+    class _BasicEnum(str, Enum):
+        A = "a"
+        B = "b"
+
+    class _BasicModel(BaseModel):
+        a: int
+        b: str
+
+    @pytest.mark.parametrize(
+        ("param_type", "value"),
+        [
+            (int, 1),
+            (float, 1.0),
+            (bool, True),
+            (str, "test"),
+            (datetime, datetime.now(tz=ZoneInfo("UTC"))),
+            (ZoneInfo, ZoneInfo("UTC")),
+            (list[int], [1, 2, 3]),
+            (dict[str, int], {"a": 1, "b": 2}),
+            (_BasicEnum, _BasicEnum.A),
+            (_BasicModel, _BasicModel(a=1, b="test")),
+            (list[_BasicModel], [_BasicModel(a=1, b="test"), _BasicModel(a=2, b="test2")]),
+            (tuple[int, str], (1, "test")),
+        ],
+    )
+    def test_get_type_schema(self, param_type: Any, value: Any):
+        schema = _get_type_schema(param_type)
+        if schema.serializer is None or schema.deserializer is None:
+            assert schema.serializer is None
+            assert schema.deserializer is None
+
+            # Check that the value is serializable and deserializable with plain json
+            assert json.loads(json.dumps(value)) == value
+            return
+
+        serialized = schema.serializer(value)
+        deserialized = schema.deserializer(serialized)
+        assert deserialized == value
 
 
 class TestToolSchema:
@@ -17,6 +62,7 @@ def sample_func(
             age: int,
             height: float,
             is_active: bool,
+            date: datetime,
             mode: TestMode = TestMode.FAST,
         ) -> bool:
             """Sample function for testing"""
@@ -44,8 +90,12 @@ def sample_func(
                     "type": "string",
                     "enum": ["fast", "slow"],
                 },
+                "date": {
+                    "type": "string",
+                    "format": "date-time",
+                },
             },
-            "required": ["name", "age", "height", "is_active"],  # 'mode' is not required
+            "required": ["name", "age", "height", "is_active", "date"],  # 'mode' is not required
         }
         assert output_schema.schema == {
             "type": "boolean",
@@ -123,3 +173,21 @@ def sample_func() -> TestModel: ...
         }
         assert output_schema.serializer is not None
         assert output_schema.serializer(TestModel(val=10)) == {"val": 10}
+
+    def test_with_datetime_in_input(self):
+        def sample_func(time: datetime) -> str: ...
+
+        input_schema, _ = tool_schema(sample_func)
+
+        assert input_schema.deserializer is not None
+        assert input_schema.deserializer({"time": "2024-01-01T12:00:00+00:00"}) == {
+            "time": datetime(
+                2024,
+                1,
+                1,
+                12,
+                0,
+                0,
+                tzinfo=ZoneInfo("UTC"),
+            ),
+        }