Measurements can be obtained from sensors to determine a state of a device. The state can be used to determine whether to provide an alert. For example, after a first alert is provided, it can be determined that the device is not accessible to the user based on the determined state, and a second alert can be suppressed at a specified time after providing the first alert. The sensor measurements can be monitored after suppressing the second alert, and a state engine can detect a change in a state based on subsequent sensor measurements. If the state change indicates that the device is accessible to the user the second alert can be provided to the user. Alerts can be dismissed based on a change in state. A first device can coordinate alerts sent to or to be provided by a second device by suppressing or dismissing such alerts.