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Tool Calling

Tools let the model do things and reach other services: search the web, read pages and files, run code, make images, or work in apps you connect, such as Notion or GitHub. In a chat, the model decides when to call the tools you have switched on. This page shows how to choose those tools and what happens when the model uses them.

What a new chat starts with​

Every new chat starts with your default capabilities. Out of the box that is 7 tools: Web search, Read web pages, Cloud browser, Read files, Run code, Time and time zones and GPT-image-2 generate and edit. The number next to Tools in the composer shows how many are on.

Changes you make in a chat apply only to that chat. To change what every new chat starts with, edit your default capabilities instead. Changing them never changes existing chats, tasks or agents.

Turn tools on or off for this chat​

  1. In the composer, click Tools. You can also click + and choose More tools (Ctrl+Shift+U).
  2. The Apply to this conversation panel opens on the Tools tab. It notes: "Changes here apply only to this chat."
  3. Find a tool with Search tools or the filters:
    • All / In use
    • All / Preset / Custom
    • All / Ready to use / Needs setup / Connected
    • All / Starred / Unstarred
  4. Use the switch next to a tool to turn it on or off. Click the star to mark tools you use often, so the Starred filter finds them quickly.
  5. To turn every tool off for this chat, click Disable all tools.

Tools panel: Apply to this conversation, with filters, switches and stars

Require the model to use these tools​

Normally the model decides whether a reply needs a tool. Turn on Require the model to use these tools when you always want a tool call: "When on, every reply calls one of the selected tools instead of the model deciding whether to." For example, switch it on with only Web search selected when every answer should come from a fresh search.

Tools that need setup​

"Built-in tools work right away. Those that need your own account or key are connected once, on their card, for every conversation and task."

  1. At the bottom of the Tools panel, click Manage Tools. Capabilities opens in a new tab, and your current draft stays in the chat.
  2. Find the tool. Its card shows its status: Ready to use, Not connected, Connected, or Pro.
  3. Use the button on the card:
    • Connect signs in to the service (for example Notion or GitHub). Use an API token instead is the alternative.
    • Add key asks for your key. It is "used only for your conversations and tasks, and never shown again after saving".
    • Use my own key appears on some ready-to-use tools.
    • Upgrade to use marks Pro tools, such as Slack or video generation. They are available on the Pro and Max plans only.
  4. Go back to the chat and switch the tool on in the Tools panel.

Tool cards with Connect, Use an API token instead, Add key and Upgrade to use

To add your own tools, see Add a custom tool and Add an MCP server. For the full list, see Use preset tools.

While the model works​

  • When the model calls a tool, the call and its result appear in the chat as part of the reply.
  • If you turn a tool off, it is no longer used, even in a reply that is already running.
  • Tools that an MCP server adds later wait for your approval before they can be used.
  • Failed tool calls are not charged.
  • To see compact usage summaries and links to call details in chats, turn on Settings → Chat Settings → Show usage and diagnostics.

Tools in tasks and agents​

Each chat, task and agent keeps its own list of tools. When you save a chat as a task, its tools and Skills are carried over and shown under Model & tools for you to review. See Save a chat as a task.