make tot follow format in 3.5-turbo

metagpt/strategy/tot.py

@@ -17,7 +17,7 @@ from metagpt.strategy.tot_schema import MethodSelect, Strategy, ThoughtSolverCon
 from metagpt.utils.common import CodeParser
 
 OUTPUT_FORMAT = """
-Output a list of jsons following the format:
+Each output should be strictly a list of nodes, in json format, like this:
 ```json
     [
         {

tests/metagpt/strategy/examples/creative_writing.py

@@ -71,7 +71,7 @@ def test_creative_writing():
     parser = TextGenParser()
     evaluator = TextGenEvaluator()
 
-    config = ThoughtSolverConfig(n_generate_sample=3, parser=parser, evaluator=evaluator)
+    config = ThoughtSolverConfig(max_step=2, n_generate_sample=1, n_select_sample=1, parser=parser, evaluator=evaluator)
 
     tot_base = TreeofThought(strategy=Strategy.BFS, config=config)
     asyncio.run(tot_base.solve(init_prompt=initial_prompt))

tests/metagpt/strategy/prompt_templates/creative_writing.py

@@ -5,13 +5,13 @@ Write a coherent passage of 4 short paragraphs. The end sentence of each paragra
 cot_prompt = """
 Write a coherent passage of 4 short paragraphs. The end sentence of each paragraph must be: {input}
 
-Make a plan then write. Your output should be of the following format:
+Make a plan then write. Your output should be like:
 
 Plan:
-Your plan here.
+<Your plan here with json format>
 
 Passage:
-Your passage here.
+<Your passage here with json format>
 """