Maximum number of tools that can be used with create_react_agent

[ksgnextuple]

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Example Code

import asyncio
import os
from importlib.metadata import version
from langchain_mcp_adapters.tools import load_mcp_tools
from langgraph.prebuilt import create_react_agent
from langchain_core.messages import SystemMessage, HumanMessage
from langchain_openai import AzureChatOpenAI
from langchain_mcp_adapters.client import MultiServerMCPClient


model = AzureChatOpenAI(
    azure_deployment="",
    azure_endpoint=,
    api_key=,
    api_version=
)

async def main():
    async with MultiServerMCPClient(
            {
                "dynamic_mcp": {
                    "url": "http://localhost:8000/sse",
                    "transport": "sse",
                }
            }
    ) as client:
        print(client.get_tools()[0])

        agent = create_react_agent(model, client.get_tools())

        messages = [
            SystemMessage(
                content=f"You are an openapi agent that can call an API. "),
            HumanMessage(
                content=f"""
                        What are some operations you can do?
                        """
            )
        ]

        agent_response = await agent.ainvoke({"messages": messages})

        print("Agent Response", agent_response)

        return agent_response

# Run the async function
if __name__ == "__main__":
    response = asyncio.run(main())
    print("Final Response", response)

Description

Facing an issue where I have an mcp server running in sse mode with 434 tools available.

Below is the error:

openai.BadRequestError: Error code: 400 - {'error': {'message': "Invalid 'tools': array too long. Expected an array with maximum length 128, but got an array with length 434 instead.", 'type': 'invalid_request_error', 'param': 'tools', 'code': 'array_above_max_length'}}

Is there a limit to the number of tools that can be used?

System Info

langchain==0.3.18
langchain-chroma==0.2.2
langchain-community==0.3.17
langchain-core==0.3.35
langchain-experimental==0.3.4
langchain-openai==0.3.5
langchain-text-splitters==0.3.6