diff --git a/src/google/adk/tools/openapi_tool/openapi_spec_parser/operation_parser.py b/src/google/adk/tools/openapi_tool/openapi_spec_parser/operation_parser.py
index 930e05c..a7bed0f 100644
--- a/src/google/adk/tools/openapi_tool/openapi_spec_parser/operation_parser.py
+++ b/src/google/adk/tools/openapi_tool/openapi_spec_parser/operation_parser.py
@@ -83,7 +83,8 @@ class OperationParser:
         schema.description = (
             description if not schema.description else schema.description
         )
-        required = param.required
+        # param.required can be None
+        required = param.required if param.required is not None else False
 
         self.params.append(
             ApiParameter(
diff --git a/tests/unittests/tools/openapi_tool/openapi_spec_parser/test_operation_parser.py b/tests/unittests/tools/openapi_tool/openapi_spec_parser/test_operation_parser.py
index 0c774f6..653590e 100644
--- a/tests/unittests/tools/openapi_tool/openapi_spec_parser/test_operation_parser.py
+++ b/tests/unittests/tools/openapi_tool/openapi_spec_parser/test_operation_parser.py
@@ -347,8 +347,8 @@ def test_get_json_schema(sample_operation):
   assert json_schema['type'] == 'object'
   assert 'param1' in json_schema['properties']
   assert 'prop1' in json_schema['properties']
-  assert 'param1' in json_schema['required']
-  assert 'prop1' in json_schema['required']
+  # By default nothing is required unless explicitly stated
+  assert 'required' not in json_schema or json_schema['required'] == []
 
 
 def test_get_signature_parameters(sample_operation):