If want anti-cut there is security mesh available.
Here's an article on why it is better than grill. (am not mesh salesman or against grill, just sharing)
https://window-elements.com/the-dangers-of-...-better-choice/If sticking with grill, allow a 2nd exit gate for emergency, ensure key and WD40 ready at all times.
Standard terrace or semi D house have party wall up to the roof, so burglar shouldn't be able to break in neighbour's roof and crawl over to break into your unit. But such incidence is not unheard of... even murder by intruder climbing from neighbour's house...perhaps the poor owner bought a non compliant house. Anyway not all linked houses you can see the fire rated party wall above the roof, as some were designed with T-beam terminating below the roof. Can check the party wall thru ceiling access to water tank usually at the Bathroom.
Regarding roof tiles security breach, can add any barrier of board, grille or mesh if not replace roof tiles with metal roofing.
Other consideration - electric fence especially detached house.