[fix] fix seed-oss-parser (#23560)

Signed-off-by: jiabin.00 <jiabin.00@bytedance.com>

tests/tool_use/test_seed_oss_tool_parser.py

@@ -102,9 +102,7 @@ def test_extract_tool_calls_no_tools(seed_oss_tool_parser):
     ],
     argnames=["model_output", "expected_tool_calls", "expected_content"],
     argvalues=[
-        ("""<seed:think>\n</seed:cot_budget_reflect>\n</seed:cot_budget_reflect>\n"""
-         """The current thinking budget is 0, so I will directly start answering the question.\n</seed:think>\n"""
-         """<seed:tool_call>\n<function=get_weather>\n"""
+        ("""<seed:tool_call>\n<function=get_weather>\n"""
          """<parameter=location>Barcelona, Spain</parameter>\n</function>\n</seed:tool_call>""",
          [
              ToolCall(function=FunctionCall(
@@ -114,10 +112,7 @@ def test_extract_tool_calls_no_tools(seed_oss_tool_parser):
                  }, ),
              ),
                       type='function')
-         ],
-         """<seed:think>\n</seed:cot_budget_reflect>\n</seed:cot_budget_reflect>\n"""
-         """The current thinking budget is 0, so I will directly start answering the question.\n</seed:think>\n"""
-         ),
+         ], None),
         (
             """<seed:think>The user\'s current thinking budget is 512.</seed:cot_budget_reflect>\nLet me analyze the """
             """question. The user wants to know the weather in Barcelona, Spain. Looking at the functions available, """

vllm/entrypoints/openai/tool_parsers/seed_oss_tool_parser.py

@@ -271,6 +271,9 @@ class SeedOssToolParser(ToolParser):
             # Extract content after think end token
             result_content = model_output[think_end_index:]
             thinking_content = model_output[:think_end_index]
+        else:
+            thinking_content = ""
+            result_content = model_output
 
         try:
             function_calls = self._get_function_calls(result_content)