The manga is not very clear, the gloves have teleportation magic, if i'm right in the novel MC realized how they were spotless of any dirt in a almost innatural way and the bitch was very careful with her movement because they were "programmed" to teeport anything touched back to the kingdom, in the manga she doesn't look so careful and is missing the explanation with readers having to guess the gloves function.
I think there is even some mistake as one of the soldiers said bitch had to give MC the gloves, when it was really just getting close enough to touch him, the novel probably even said how that thing would teleport away his barrier too, makign possible to touch him, but not sure, I could be misremembering it.
I don't know the tool limitations, I think they were alwasy "on" , but no idea if there was a set amount of stuff they could teleport and if MC could have drained the tool with no stop barriers, I read this novel chapter months ago out of curiosity and didn't go beyond.