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 45f81b46fd1..76dda70205d 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
@@ -142,6 +142,7 @@ def _process_request_body(self):
 
       if schema and schema.type == 'object':
         properties = schema.properties or {}
+        required_properties = set(schema.required or [])
         for prop_name, prop_details in properties.items():
           self._params.append(
               ApiParameter(
@@ -149,6 +150,7 @@ def _process_request_body(self):
                   param_location='body',
                   param_schema=prop_details,
                   description=prop_details.description,
+                  required=prop_name in required_properties,
                   py_name=self._get_py_name(prop_name),
               )
           )
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 7df9a9bff8e..e90453937ce 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
@@ -105,6 +105,31 @@ def test_process_request_body(sample_operation):
   assert parser._params[1].param_location == 'body'
 
 
+def test_required_request_body_properties_are_required_parameters():
+  """Required body properties appear in the generated parameter schema."""
+  operation = Operation(
+      operationId='createSpace',
+      requestBody=RequestBody(
+          content={
+              'application/json': MediaType(
+                  schema=Schema(
+                      type='object',
+                      required=['spaceName'],
+                      properties={
+                          'spaceName': Schema(type='string'),
+                          'description': Schema(type='string'),
+                      },
+                  )
+              )
+          }
+      ),
+  )
+
+  parser = OperationParser(operation)
+
+  assert parser.get_json_schema()['required'] == ['space_name']
+
+
 def test_process_request_body_array():
   """Test _process_request_body method with array schema."""
   operation = Operation(