Do stories have to start with user intent? Inconsistent documentation

Does a story have to begin with a user’s intent, or may it be anything else (i.e. an action)?

The notification box at the end of the checkpoints section in the documentation implies that stories should always start with a checkpoint or an intent (“Unlike regular stories, checkpoints are not restricted to starting with user input.”).

However, the “Creating Logical Breaks in Stories” shows an example where stories start with an action, namely a bot utterance, instead of an intent.

Is there a clarification on which lines may start stories and which may not? Does it always have to be an intent (and how would you solve the problem in the second documentation part then)? May it be any kind of action like an active_loop or a custom action, or only utterances?