When I speak to an agent, siri, or whatnot, I am always worried that they will assume I'm done talking when I'm thinking. Sometimes I need a many-seconds pause. Even maybe a minute… For Sire and such, I want to ask something simple "Hey Siri, remind me to call dad tomorrow". Easy. But for Claude and such, I want to go on a long monolog (20s, a minute, multi-minutes).
To me, be the best solution would be semantic + keyword + silence.
Hey Agent, blablablabla, thank you.
Hey Agent, blablablabla, please.
Hey Agent, blablablabla, oops cancel.