diff --git a/google/genai/_extra_utils.py b/google/genai/_extra_utils.py
index e0fb9c105..9cd80be2a 100644
--- a/google/genai/_extra_utils.py
+++ b/google/genai/_extra_utils.py
@@ -438,6 +438,8 @@ def should_disable_afc(
     return True
 
   # Default to enable AFC if not specified.
+  if not config_model.tools or len(config_model.tools) == 0:
+    return True
   if (
       not config_model.automatic_function_calling
       or config_model.automatic_function_calling.disable is None
diff --git a/google/genai/tests/afc/test_should_disable_afc.py b/google/genai/tests/afc/test_should_disable_afc.py
index 188bf2b57..c89085f24 100644
--- a/google/genai/tests/afc/test_should_disable_afc.py
+++ b/google/genai/tests/afc/test_should_disable_afc.py
@@ -26,7 +26,7 @@ def test_config_is_none():
 
 
 def test_afc_config_unset():
-  assert should_disable_afc(types.GenerateContentConfig()) is False
+  assert should_disable_afc(types.GenerateContentConfig()) is True
 
 
 def test_afc_enable_unset_max_0():
@@ -71,6 +71,9 @@ def test_afc_enable_unset_max_1():
               automatic_function_calling=types.AutomaticFunctionCallingConfig(
                   maximum_remote_calls=1,
               ),
+              tools=[types.Tool(function_declarations=[
+                  types.FunctionDeclaration(name='tool_name')
+              ])],
           )
       )
       is False
@@ -80,7 +83,10 @@ def test_afc_enable_unset_max_1():
 def test_afc_enable_unset_max_1_0():
   assert (
       should_disable_afc(
-          {'automatic_function_calling': {'maximum_remote_calls': 1.0}}
+          {
+              'automatic_function_calling': {'maximum_remote_calls': 1.0},
+              'tools': [{'function_declarations': [{'name': 'tool_name'}]}]
+          }
       )
       is False
   )
@@ -157,6 +163,9 @@ def test_afc_enable_true_max_unset():
               automatic_function_calling=types.AutomaticFunctionCallingConfig(
                   disable=False,
               ),
+              tools=[types.Tool(function_declarations=[
+                  types.FunctionDeclaration(name='tool_name')
+              ])],
           )
       )
       is False
@@ -210,5 +219,5 @@ def test_afc_enable_true_max_1():
               ),
           )
       )
-      is False
+      is True
   )