* To describe the characters. Playwrights use character descriptions to introduce their characters to the audience. These descriptions can be found at the beginning of the play or in the dialogue between characters.
* To describe the setting. Playwrights use setting descriptions to create the world of the play for the audience. These descriptions can be found at the beginning of the play or in the dialogue between characters.
* To describe the action. Playwrights use stage directions to describe the physical movements of the characters and the objects on the stage. These directions can be found throughout the play.
* To describe the tone of the play. Playwrights use stage directions to indicate the tone of the play, such as whether it is serious, comedic, or tragic. These directions can be found throughout the play.
Therefore, the answer is "To describe the characters."