1. A computer-implemented method comprising: determining, by a voice action system, that a software application installed on a user device is compatible with a new voice action, wherein the software application is different from the voice action system and the new voice action is specified by an application developer of the software application; determining, by the voice action system, that the software application installed on the user device is compatible with one or more other voice actions; identifying, by the voice action system, one or more trigger terms for triggering the software application to perform the new voice action; identifying, by the voice action system, one or more trigger terms for triggering the software application to perform the one or more other voice actions; ranking, by the voice action system, the new voice action and the one or more other voice actions; biasing, by the voice action system, an automatic speech recognizer to prefer the identified one or more trigger terms of the new voice action over the trigger terms of the one or more other voice actions, wherein the automatic speech recognizer is biased based at least on the ranking; obtaining, by the voice action system, a transcription of an utterance generated by the biased automatic speech recognizer; determining, by the voice action system, that the transcription of the utterance generated by the biased automatic speech recognizer includes a particular trigger term included in the identified one or more trigger terms; and triggering, by the voice action system, execution of the new voice action based at least on determining that the transcription of the utterance generated by the biased automatic speech recognizer includes the particular trigger term.