The Idling states are progressive. The animation services begin using the Level 1 assignments for the first idle period, and use the Level 2 animations for the second. After this, the idle cycle progresses to the Level 3 assigned animations and remains in this state until canceled, such as when a new animation request begins.
Design animations for the Idling states to communicate the state of the character, but not to distract the user. The animations should appropriately reflect the responsiveness of the character in subtle but clear ways. For example, glancing around or blinking are good animations to assign to the IdlingLevel1 state. Reading animations work well for the IdlingLevel2 state. Sleeping or listening to music with headphones are good examples of animations to assign to the IdlingLevel3 state. Animations that include many or large movements are not well suited for idle animations because they draw the user's attention. Because Idling state animations are played frequently, provide several Idling state animations, especially for the IdlingLevel1 and IdlingLevel2 states.
Note that an application can turn off the automatic idle processing for a character and manage the character's Idling state itself. The Agent Idling states are designed to help you avoid any situation where the character has no animation to play. A character image that does not change after a brief period of time is like an application displaying a wait pointer for a long time, which detracts from the sense of believability and interactivity. Maintaining the illusion does not take much: sometimes just an animated blink, visible breath, or body shift.