query_engine_tools_step = [
    QueryEngineTool(
        query_engine=myqueryengine.as_query_engine(similarity_top_k=5),
        metadata=ToolMetadata(
            name="doc_agent",
            description="Useful for getting documentation."),
    )
]
agent = ReActAgent.from_tools(query_engine_tools_step, llm=llm, verbose=True, context_window=2000, max_iterations=100)
react_system_prompt = PromptTemplate(react_system_header_str)
agent.update_prompts({"agent_worker:system_prompt": react_system_prompt})

react_system_header_str = """ ## Tools
        You are responsible for using the tools in any sequence you deem appropriate to complete the task at hand.
        You have access to the following tools, all of which takes a simple string query as an argument: 
  
        {doc_agent}
 """