# Day 4 - LLM - Tool Calling

> Source: <https://dev.to/technonotes/day-4-llm-tool-calling-i9p>
> Published: 2026-09-26 19:22:00+00:00

# 
  
  
  Tool Calling

- Asking some query to the LLM.
- LLM is like a phone book , it can't call on its own. With some tools only it will.
- Tools are nothing but FUNCTIONS.

- Tool calling is also called as FUNCTION Calling.
- Its a method , which models reliably connect and interact with external tools like API , database or knowledge base.
- LLM gets set of tools and it decides which tools needs to be invoked for a specific user query and to complete a given task.

- Next level of this is " MCP ".

## 
  
  
  Code

- I am just Mocking the data.
- In Langchain, tool is there . Tool is like the method.its like a rapper functionality.
- If we write any method and mention "[@tool](https://dev.to/tool) " means --> its called**DECORATOR** . Its like tool and object.
- tool_map is a dictionary.
- ChatGroq --> if langchain is integrated with Groq.

# 
  
  
  Notes

- Functions are nothing but TOOLS.
- llm will have many functions.
- Infra provider for LLM is **Groq site** . Creat API key. This is a**Groq client** --> it will communicate to cloud LLMs. Eg., llama3 , gpt-oss120 billion model, for this we needs API key.

## 
  
  
  Implementation

## 
  
  
  Advantages

- Real-time data access and information retrieval
- Reducing Hallucinations 
- Extends capability of LLMs

## 
  
  
  Disadvantages

- Token consumption and Cost
- Cost & Latency
- Security & Safety Risks

# 
  
  
  Questions