[wool_gather]

I've found just declining these no-info meetings to be an effective way to combat the time loss. It's most constructive to send an email alongside saying something like "please share an agenda or materials for this", but that can vary based on context too. And you can even decline after that happens: "Thanks for the details. I'm sorry, but I cannot take the time away from X right now to attend this. Next week may be possible."

If somebody really needs my time, they can tell me why -- or go through my manager which they should be doing anyways.

[deathanatos]

You say that, and it sounds like it ought to work, and yet…

I had to do that to a co-worker, and all I got back was "Product Foo". Okay, but what about Product Foo? Blood from a stone, every damn time, and it wears me down.

[wool_gather]

Well, that kind of reply is just rude, and personally I'd probably ignore it and leave the meeting declined. If it comes up later, "Your reply about the meeting? No, I don't think...oh, I did see it, right. I assumed there was more info coming; I'm totally focussed on $X right now, you know."

[AlexCoventry]

"I'm sorry, my responsibilities don't leave me any time to discuss Foo in general terms at the moment. If you really you need me to, please raise it with $manager, and we will reprioritize my duties."

[duxup]

If that's an option, yeah I think that is a really good route.

It wasn't in my situation, mostly because everyone sucked at meetings at an astounding level. But I'm not there anymore thankfully!