Tools & Actions

Tools (also called function calling) let a model do more than talk — it can call functions you define to fetch data or take actions in your game. You describe the available tools; the model decides when to call one and with what arguments; you run it and return the result; the model continues with that result in hand.

Tools are available only on tool-capable models.

Defining tools

Each tool has a name, a description, and a parameter schema. You pass the set of tools with the request:

{
  "tools": [
    {
      "name": "get_player_inventory",
      "description": "Look up the player's current items",
      "parameters": {
        "type": "object",
        "properties": { "playerId": { "type": "string" } },
        "required": ["playerId"]
      }
    }
  ]
}

Controlling tool use

tool_choice controls whether and how the model uses tools:

Multi-step actions

A model can call tools across multiple steps — call one, read the result, call another — to complete a task before giving its final reply. This is what turns tool calling into actions: the model drives a short workflow using your functions.

When to use it

• Read game state (inventory, quests, stats) the model wouldn't otherwise know.
• Take actions — grant an item, move an NPC, update a record.
• Ground replies in live data instead of the model's training.

For the exact call in your language, see the JavaScript, Unity, or Unreal text generation guide.