MCP, Tool Use & the Agent Ecosystem
Understand how AI connects to external tools, APIs, and data sources.
What is Tool Use?
Tool use (also called function calling) is how AI models interact with the real world. Instead of just generating text, the model can:
- Search the web — Find current information
- Run code — Execute Python, JavaScript, SQL
- Call APIs — Access external services (weather, stock prices, CRMs)
- Read files — Process documents, spreadsheets, images
- Take actions — Send emails, create calendar events, update databases
When ChatGPT browses the web or runs code in its Code Interpreter, it's using tool use.
MCP: The Universal Connector
MCP (Model Context Protocol) is an open standard created by Anthropic that lets AI models connect to any external tool or data source through a standardized interface.
Think of MCP like USB for AI — a universal connector that works with any tool. Instead of each AI model needing custom integrations with every service, MCP provides one standard that works everywhere.
MCP is rapidly being adopted across the AI ecosystem, enabling AI agents to access databases, file systems, APIs, and applications through a consistent interface.
Enable ChatGPT's browsing and Code Interpreter features. Try a task that requires both: "Search for the current S&P 500 price, then create a Python chart showing its performance over the past year." Observe how the AI uses multiple tools.
- ✓Tool use lets AI interact with the real world, not just generate text
- ✓AI can search the web, run code, call APIs, read files, and take actions
- ✓MCP is an open standard for connecting AI to any external tool
- ✓Tool use is what transforms chatbots into useful agents