ConversationalAgent/CHAT_CONVERSATIONAL_REACT_DESCRIPTION dosen't work well with ChatOpenAI 3.5 and Claude models
Labels: name: area: agent, name: auto:bug, name: area: models

### System Info

Python 3.10

### Who can help?

@hw

### Information

- [X] The official example notebooks/scripts
- [ ] My own modified scripts

### Related Components

- [X] LLMs/Chat Models
- [ ] Embedding Models
- [ ] Prompts / Prompt Templates / Prompt Selectors
- [ ] Output Parsers
- [ ] Document Loaders
- [ ] Vector Stores / Retrievers
- [ ] Memory
- [X] Agents / Agent Executors
- [ ] Tools / Toolkits
- [ ] Chains
- [ ] Callbacks/Tracing
- [ ] Async

### Reproduction

I tried with 3.5 and Claude models, but it rarely generates a reply to the prompt preset (like below) when I use the conversation agent. GPT 4 works fine.

```
Thought: Do I need to use a tool? Yes
Action: the action to take, should be one of [{tool_names}]
Action Input: the input to the action
Observation: the result of the action
```

When you have a response to say to the Human, or if you do not need to use a tool, you MUST use the format:

```
Thought: Do I need to use a tool? No
{ai_prefix}: [your response here]
```

This is my code:
![image](https://github.com/langchain-ai/langchain/assets/44308338/e2ddb385-17f5-4cbc-a681-ad5ccfad27df)

Errors:


> Entering new AgentExecutor chain...
Thought: Do I need to use a tool? Yes
Action: Search
Action Input: Weather in London today
Observation: London, England, United Kingdom 10-Day Weather Forecaststar_ratehome ; Temperature. High. 77 ; Rain/Snow Depth. Precipitation. 0 ; Temperature. High. 80 ...
Thought:Traceback (most recent call last):
  File "/Users/joey/Library/CloudStorage/OneDrive-Personal/Code/GPT/agent081123.py", line 254, in <module>
    print(agent_chain.run(user_input))
  File "/opt/homebrew/anaconda3/envs/XXX/lib/python3.10/site-packages/langchain/chains/base.py", line 475, in run
    return self(args[0], callbacks=callbacks, tags=tags, metadata=metadata)[
  File "/opt/homebrew/anaconda3/envs/XXX/lib/python3.10/site-packages/langchain/chains/base.py", line 282, in __call__
    raise e
  File "/opt/homebrew/anaconda3/envs/XXX/lib/python3.10/site-packages/langchain/chains/base.py", line 276, in __call__
    self._call(inputs, run_manager=run_manager)
  File "/opt/homebrew/anaconda3/envs/XXX/lib/python3.10/site-packages/langchain/agents/agent.py", line 1036, in _call
    next_step_output = self._take_next_step(
  File "/opt/homebrew/anaconda3/envs/XXX/lib/python3.10/site-packages/langchain/agents/agent.py", line 844, in _take_next_step
    raise e
  File "/opt/homebrew/anaconda3/envs/XXX/lib/python3.10/site-packages/langchain/agents/agent.py", line 833, in _take_next_step
    output = self.agent.plan(
  File "/opt/homebrew/anaconda3/envs/XXX/lib/python3.10/site-packages/langchain/agents/agent.py", line 457, in plan
    return self.output_parser.parse(full_output)
  File "/Users/joey/Library/CloudStorage/OneDrive-Personal/Code/GPT/agent081123.py", line 225, in parse
    raise OutputParserException(f"Could not parse LLM output: `{text}`")
langchain.schema.output_parser.OutputParserException: Could not parse LLM output: `Do I need to use a tool? No`
(XXX) joey@Joey-MBP GPT% 

### Expected behavior

Should have no parser error and generate the same format response as the prompt.