Which tool cannot be used to annotate a designated area?

The tool that cannot be used to annotate a designated area is the Smart Dimension tool. Smart Dimension is primarily used to create dimensions that accurately depict the size and relationship of features in a 2D or 3D design. It measures distances, angles, and radii, allowing designers to establish precise dimensions within their drawings. However, it is not specifically intended for general annotation of an area, such as providing descriptive information or commentary.

In contrast, the other options—Text box, Leader line, and Data note—are explicitly designed for annotating areas within a drawing or model. A Text box allows users to add text for explanations or labels, a Leader line is useful for pointing out specific features and connecting notes to them, while a Data note helps to display specific data associated with elements in the design. Thus, these tools serve the purpose of annotating and offering additional context, which is not the primary function of the Smart Dimension tool.