How to disable tools call in parallel when using AgentExecutor?

[Lin-jun-xiang]

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Example Code

openai_client = AsyncOpenAI(api_key=OPENAI_API_KEY)
langchain_llm_client = ChatOpenAI(
    model='gpt-4o',
    temperature=0.,
    api_key=OPENAI_API_KEY,
    streaming=True,
    max_tokens=None,
    verbose=LANCHAIN_VERBOSE,
    max_retries=5
)
agent = create_tool_calling_agent(langchain_llm_client, tools, AGENT_PROMPT)
agent_executor = AgentExecutor(
    agent=agent,
    tools=tools,
    verbose=LANCHAIN_VERBOSE,
    return_intermediate_steps=True
)

async for event in agent_executor.astream_events(
    {
        "input": formatted_history_query,
        "tool_names": tool_names,
        "agent_scratchpad": lambda x: format_to_openai_tool_messages(x["intermediate_steps"]),
    },
    version='v2'
):
          ...

Description

How can I disable the tool calling in parallel ?

Some times the tools should be call like:
tool1 -> tool2 -> tool3....

However, the AgentExecutor will call too1, tool2, tool3 in the same time.

System Info

System Information

OS: Windows
OS Version: 10.0.26100
Python Version: 3.11.0 (main, Oct 24 2022, 18:26:48) [MSC v.1933 64 bit (AMD64)]

Package Information

langchain_core: 0.3.43
langchain: 0.3.20
langchain_community: 0.3.19
langsmith: 0.3.13
langchain_google_genai: 2.0.11
langchain_openai: 0.3.8
langchain_text_splitters: 0.3.6
langgraph_sdk: 0.1.58

Optional packages not installed

langserve

Other Dependencies

aiohttp<4.0.0,>=3.8.3: Installed. No version info available.
async-timeout<5.0.0,>=4.0.0;: Installed. No version info available.
dataclasses-json<0.7,>=0.5.7: Installed. No version info available.
filetype: 1.2.0
google-ai-generativelanguage: 0.6.16
httpx: 0.28.1
httpx-sse<1.0.0,>=0.4.0: Installed. No version info available.
jsonpatch<2.0,>=1.33: Installed. No version info available.
langchain-anthropic;: Installed. No version info available.
langchain-aws;: Installed. No version info available.
langchain-cohere;: Installed. No version info available.
langchain-community;: Installed. No version info available.
langchain-core<1.0.0,>=0.3.34: Installed. No version info available.
langchain-core<1.0.0,>=0.3.41: Installed. No version info available.
langchain-core<1.0.0,>=0.3.42: Installed. No version info available.
langchain-deepseek;: Installed. No version info available.
langchain-fireworks;: Installed. No version info available.
langchain-google-genai;: Installed. No version info available.
langchain-google-vertexai;: Installed. No version info available.
langchain-groq;: Installed. No version info available.
langchain-huggingface;: Installed. No version info available.
langchain-mistralai;: Installed. No version info available.
langchain-ollama;: Installed. No version info available.
langchain-openai;: Installed. No version info available.
langchain-text-splitters<1.0.0,>=0.3.6: Installed. No version info available.
langchain-together;: Installed. No version info available.
langchain-xai;: Installed. No version info available.
langchain<1.0.0,>=0.3.20: Installed. No version info available.
langsmith-pyo3: Installed. No version info available.
langsmith<0.4,>=0.1.125: Installed. No version info available.
langsmith<0.4,>=0.1.17: Installed. No version info available.
numpy<3,>=1.26.2: Installed. No version info available.
openai<2.0.0,>=1.58.1: Installed. No version info available.
orjson: 3.10.15
packaging: 24.2
packaging<25,>=23.2: Installed. No version info available.
pydantic: 2.10.6
pydantic-settings<3.0.0,>=2.4.0: Installed. No version info available.
pydantic<3.0.0,>=2.5.2;: Installed. No version info available.
pydantic<3.0.0,>=2.7.4: Installed. No version info available.
pydantic<3.0.0,>=2.7.4;: Installed. No version info available.
pytest: Installed. No version info available.
PyYAML>=5.3: Installed. No version info available.
requests: 2.32.3
requests-toolbelt: 1.0.0
requests<3,>=2: Installed. No version info available.
rich: 13.9.4
SQLAlchemy<3,>=1.4: Installed. No version info available.
tenacity!=8.4.0,<10,>=8.1.0: Installed. No version info available.
tenacity!=8.4.0,<10.0.0,>=8.1.0: Installed. No version info available.
tiktoken<1,>=0.7: Installed. No version info available.
typing-extensions>=4.7: Installed. No version info available.
zstandard: 0.23.0