Defining multiple tools

Designing Agentic Systems with LangChain

Dilini K. Sumanapala, PhD

Founder & AI Engineer, Genverv, Ltd.

Integrating multiple tools

A bot with multiple tools

   

  • Add multiple custom tools

  • Automate tool selection per query

Designing Agentic Systems with LangChain

Enhancing an education chatbot

People reading, sat on large books.

 

  • Look up historical events

  • Check palindromes:

     

    • level = level

    • top spot = tops pot

Designing Agentic Systems with LangChain

Multiple ways to build tools

 

  • Invoke the LLM

    Look up historical dates using natural language inputs, eg. "5th of November"
      Agent: The 5th of November is famous for the Gunpowder treason and 
  plot...

  • Python code

    Find palindromes by directly comparing strings, eg. string == string[::-1]
      Agent: Yes, "madam" is a palindrome...
Designing Agentic Systems with LangChain

Historical events tool

# Use a decorator to label the tool and set the input format to string
@tool

def date_checker(date: str) -> str:

    """Provide a list of important historical events for a given date in any format."""

    try:
          # Invoke the LLM to interpret the date and generate historical events
        answer = llm.invoke(f"List important historical events that occurred on {date}.")


        # Return the response
        return answer.content


    # Set an exception block for errors in retrieval
    except Exception as e:
        return f"Error retrieving events: {str(e)}"
Designing Agentic Systems with LangChain

Palindrome tool

@tool

# Set input format to string
def check_palindrome(text: str):

    """Check if a word or phrase is a palindrome."""


    # Remove non-alphanumeric characters and convert to lowercase
    cleaned = ''.join(char.lower() for char in text if char.isalnum())


    # Check if the reversed text is the same as original text
    if cleaned == cleaned[::-1]:
        return f"The phrase or word '{text}' is a palindrome."
    else:
        return f"The phrase or word '{text}' is not a palindrome."
Designing Agentic Systems with LangChain

Binding multiple tools

# Import modules required for defining tool nodes
from langgraph.prebuilt import ToolNode


# List of tools
tools = [wikipedia_tool, date_checker, check_palindrome]


# Pass the tools to the ToolNode()
tool_node = ToolNode(tools)


# Bind tools to the LLM
model_with_tools = llm.bind_tools(tools)
Designing Agentic Systems with LangChain

Let's practice!

Designing Agentic Systems with LangChain

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