What keeps routes away from residential areas?

I can see that my CoMaps does not route through houses' yards. And, if the route either begins or ends at a yard, it does allow crossing there.So, it is respecting some OSM tag. What tags are those that cause the routing to avoid residential yards?

For example, a route from 60.219, 25.065 to the metro station at 60.224, 25.076 is routed straight through the yard of a school with 7-year-old pupils, which is really not okay during school hours. The school's yard is marked as an area of type School Grounds, but of course many schools where it is no problem at all to walk through their areas can have the same feature... So, what are the tags that cause the routing algorithm of CoMaps/Organic Maps/Maps.me to avoid houses' yards? What tags can I add to the school yards in OSM in order to prevent routing through them?