A concrete example
The model figures out it needs to check a price, calls the search tool, then writes the answer using the result.
Why it matters
Without tools, an agent stays trapped in the conversation. With tools, it can act on a real system.
You see it in agents that send an email, read a file, search the web, or call an API.
Don't mix it up with
MCP: MCP, short for Model Context Protocol, is a standard that lets an AI connect cleanly to tools and data.
Agentic workflow: An agentic workflow is a sequence of steps where the AI plans, uses tools, checks its work, and keeps going until it hits the result.
Common mistakes
- Handing over too many tools with no rules.
- Letting the agent trigger a sensitive action without approval.
- Not logging the tool calls.
Quick checklist
- First I check whether the word names a concept, a tool, a risk, or a metric.
- I tie it to a concrete case: The model figures out it needs to check a price, calls the search tool, then writes the answer using the result.
- I keep the main trap in mind: Handing over too many tools with no rules.
Quick questions
What is Tool use / Function calling in AI?
Tool use lets a model call an external tool instead of only replying with text.
Where will I run into Tool use / Function calling?
You see it in agents that send an email, read a file, search the web, or call an API.
Which word should I read next?
Start with MCP, Agentic workflow, Guardrail.