Doesn’t matter that you don’t know what it does; get one – you’re a bloke and that’s a good enough reason.
This is stupid, and quite frankly sexist ‘advice’. Best ignored. The best way to learn about power tools is to speak to someone who is experienced in using them, and perhaps even get them to show you how to use them. This neanderthal attitude about ‘man need tool’ puts people in hospital. Why unnecessarily burden our already knackered NHS? Sorry; I’m sure the comment was meant in jest, but foolish male go driven bravado is one of my pet hates, as I’ve seen too many nasty avoidable incidents involving men and power tools.
Rant over. That said, an oscillating multitool is reasonably safe, used correctly. A good safety tip is to remove the battery or unplug the tool when changing bits. Common sense. Such tools are really useful for cutting through plasterboard say for installing a new power socket, but really do take care that you don’t cut into live cables. Yep, seen that done. They are very versatile, but more a jack of all trades type tool. Good for reaching places inaccessible to other tools.
https://www.sgs-engineering.com/help-advice/uses-for-your-oscillating-multi-tool/?gclid=CjwKCAjw5P2aBhAlEiwAAdY7dC8C57PGaiZOoxYHqXy4VHVpNauJF-x2PMalAr1a05M_nCuVKC6SAhoCY6gQAvD_BwE