Even brief information could still be useful. Information theory is tricky. I think it was Victor Hugo who had a conversation with his publisher regarding the sales of Les Miserables. He sent a "?" and got a "!" back. I guess that was a bit like sending a pointer to something else. If a civilization 10000 ly away sent: "May You be touched by his Noodly Appendage." That might change a lot. Or maybe they send 100 lines of insanely clever self modifying code which can form the foundation of a good AI which then can become a technological singularity. Or maybe some constants, science formulas... or maybe schematics for a Warp/FTL drive if there is such a thing.