Hi, is it possible to prevent an intent from starting a session but allow it to continue the session?
My goal is to implement a dialog session like this:
USER: Turn off the light -> intent [TurnOffLight]
ASSISTANT: Which light?
USER: The light xyz -> intent [LightParameter]
LighParameter intent should not be used to initiate the session.
Probably not what you want, but …
In my case, if the light is not named (according to which room it is in), my automation assumes the light in the room where the Rhasspy satellite is located.
I can say “turn on the living room light” in any room to turn on the bulb in the living room;
but if I just say “turn on the light” when I am in the bedroom, it works out that the Rhasspy satellite in the bedroom has initiated the intent, and so will turn on the light in the bedroom.
And if I say “Turn on the light” when in the kitchen where there is no LIFX bulb … well i get what I deserve 
Of course it helps that I only have 3 LIFX bulbs so far; and that I have tried to keep my intents simple (have avoided attempting the interactions as you describe).
Disabling intents (globally or for a specific satellite) is possible, see Lost in dialogues: customData, intentFilter and dialogueManager/configure.
BUT: disabled dialogues might leed to “intentNotRecognized” results, so imo it’s recommended to integrate some “keywords” in the answer sentences to distinguish them clearly form “regular” sentences.
Best way still is to avoid the necessity for clarification, especially by “guessing” the missing parts based on the “environment” like the room, already turned on lights (e.g. for brighness) or kind of priorization.