Yes, the shed is storage and the ‘workshop’ – i.e., whilst I don’t leave the tools on the bench, it wouldn’t take a genius to work out where they are, so all the kit is there to strip the bike down if they did get in.
I had though about building a lockable area under the bench to keep the tools in to at least slow them down (which I may still do – I custom built the bench from steel box sectionto fit the shed, so any ‘extras’ are but a but a few welds away!! ;-), but if they bought a multi-tool with them, that would be enough to clean most bits off the frame. This is essentially what the alarm is for – if they do get in, hopefully it will deter them from hanging around long enough to start stripping the bikes down as they can’t be walked out of the shed quickly.
My biggest worry is, if they do get in once, but can’t get away with anything they’ll come back again better prepared…