.opencode/node_modules/@ai-sdk/provider/src/language-model/v2/language-model-v2-tool-choice.ts

export type LanguageModelV2ToolChoice =
  | { type: 'auto' } // the tool selection is automatic (can be no tool)
  | { type: 'none' } // no tool must be selected
  | { type: 'required' } // one of the available tools must be selected
  | { type: 'tool'; toolName: string }; // a specific tool must be selected: