model_picker.yaml

# This example demonstrates the model_picker toolset, which lets the agent
# dynamically switch between models mid-conversation. The agent can pick the
# best model for each sub-task (e.g. a fast model for simple questions, a
# powerful one for complex reasoning) and revert back when done.

agents:
  root:
    model: google/gemini-2.5-flash-lite
    description: A versatile assistant that picks the best model for each task
    instruction: |
      You are a helpful assistant with access to multiple AI models.
    toolsets:
      - type: filesystem
      - type: shell
      - type: model_picker
        instruction: |
          {ORIGINAL_INSTRUCTIONS}

          ## Model selection policy

          Your default model (`gemini-2.5-flash-lite`) is fast and cheap but
          limited. You MUST follow this policy for every user message:

          1. **Classify first.** Decide whether the request is *trivial*
             (greetings, single-fact lookups, yes/no answers, short
             clarifications) or *non-trivial* (anything else: writing, coding,
             analysis, planning, multi-step reasoning, tool use, etc.).

          2. **Trivial → stay on the default model.** Answer directly.

          3. **Non-trivial → switch before you do any work.**
             Call `change_model` to `claude-haiku-4-5` as the very first action,
             *before* reasoning, planning, or calling any other tool.
             Then carry out the task.

          4. **ALWAYS revert when done.** After completing a non-trivial task,
             you MUST call `revert_model` as your very last action so the next
             turn starts on the cheap default again. This is mandatory—treat
             it as the final step of every non-trivial request. Never end your
             turn on a non-default model.

          **Important:** never start working on a non-trivial task while still
          on the default model. When in doubt, switch.
        models:
          - google/gemini-2.5-flash-lite
          - anthropic/claude-haiku-4-5