Interface ToolBuilder

packages/core/src/tools/tools.ts:93–138

 * Interface for a tool builder that validates parameters and creates invocations.
 */
export interface ToolBuilder<
  TParams extends object,
  TResult extends ToolResult,
> {
  /**
   * The internal name of the tool (used for API calls).
   */
  name: string;

  /**
   * The user-friendly display name of the tool.
   */
  displayName: string;

  /**
   * Description of what the tool does.
   */
  description: string;

  /**
   * The kind of tool for categorization and permissions
   */
  kind: Kind;

  /**
   * Function declaration schema from @google/genai.
   */
  schema: FunctionDeclaration;

  /**
   * Whether the tool's output should be rendered as markdown.
   */
  isOutputMarkdown: boolean;

  /**
   * Whether the tool supports live (streaming) output.
   */
  canUpdateOutput: boolean;

  /**
   * Validates raw parameters and builds a ready-to-execute invocation.
   * @param params The raw, untrusted parameters from the model.
   * @returns A valid `ToolInvocation` if successful. Throws an error if validation fails.
   */
  build(params: TParams): ToolInvocation<TParams, TResult>;
}

/**
 * New base class for tools that separates validation from execution.