Which models support function calling?

GPT-4 and GPT-3.5 (OpenAI), Claude 3 (Anthropic), Gemini (Google), and many open-source models. Implementation details vary - check specific documentation for each.

How do I write good function descriptions?

Be specific about what the function does and when to use it. Include parameter descriptions. The LLM uses descriptions to decide when and how to call functions - clarity is crucial.

Can the AI call multiple functions?

Yes, modern models support parallel function calling (multiple at once) and sequential calling (based on results). Design your functions and prompts to support the patterns you need.

What about security with function calling?

Critical considerations: validate all parameters, limit function capabilities appropriately, implement authorisation checks, log all function calls, and never trust LLM output directly for sensitive operations.

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Function Calling

An LLM capability to output structured requests to external functions or APIs, enabling AI to take actions like searching databases or executing code.

In-Depth Explanation

Function calling (also called tool use) is a capability that allows LLMs to output structured requests to external functions, tools, or APIs. This bridges the gap between AI understanding and AI action.

How function calling works:

Define available functions with parameters
User sends a request
LLM decides if a function is needed
LLM outputs a structured function call
Your code executes the function
Results are returned to the LLM
LLM generates final response using results

Function definition includes:

Name: What the function is called
Description: What it does (helps LLM decide when to use it)
Parameters: Input schema with types and descriptions
Required vs optional parameters

Common function calling use cases:

Database queries
API integrations
Calculations
Web searches
File operations
System actions

This capability transforms chatbots into agents that can take real actions, not just provide information.

Business Context

Function calling transforms chatbots into capable agents that can check inventory, process orders, or query your systems in real-time.

How Clever Ops Uses This

We implement function calling for Australian businesses to create AI assistants that can actually do things - check orders, update records, send notifications, and integrate with business systems.

Example Use Case

"AI determines it needs to check order status and outputs: {"function": "get_order", "order_id": "12345"} which your code executes against your database."

Frequently Asked Questions

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