Music licensing is the venue's responsibility. In Ireland that generally means IMRO and PPI licences for live and recorded music on your premises.
GigSpace doesn't obtain, hold or check those licences, and booking a gig through GigSpace doesn't mean any licence is in place. Neither the agency nor the act covers it for you.
The same goes for the premises itself: safety, capacity, your own insurance, and the conditions the act performs in are yours.
Tell the agency in advance about anything the act needs to know: load-in and access, sound limits, curfews, or anything restricted. It's much easier to plan for than to discover at eight o'clock.