Tool calling
When the AI asks another app for help: search, maths, your calendar.
On its own, an AI can only write text from what it learned. Tool calling lets it ask other programs to do things: search the web, run a calculation, check a calendar, look up the weather. The app runs the tool, hands back the result, and the AI uses it in its answer.
How it works
- 01The AI notices a tool would help, like "I need this Saturday's weather".
- 02It sends a structured request to that tool, with details such as the city and the date.
- 03The tool returns the result, and the AI turns it into a normal answer for you.
Calling the pharmacy
You don't know whether the pharmacy has the children's fever syrup in stock. Instead of guessing, you call, ask one specific question and pass the answer on. Tool calling is the AI making that call. It knows when it doesn't have the information, asks the right tool, then answers you with the real result.
Where you'll use it
Weather-proof plans
"Zoo on Saturday?" The AI checks the forecast before it answers.
Live numbers
AI that pulls today's bookings or sales from your tools instead of guessing.
Exact maths
Splitting costs or scaling a recipe, calculated rather than estimated.
Your nap-time experiment
Ask something the AI can't know from memory and watch it reach for a tool. Make sure web search is turned on; many apps show a small "searching" step.
I'm planning a family day out in Zurich this Saturday with a toddler. 1. Check the weather forecast for Saturday. 2. Based on the weather, suggest one indoor and one outdoor option. 3. Calculate the total cost for 2 adults and a 2-year-old if adult tickets cost CHF 29 and kids under 6 go free. Tell me which tools you used for each step.