J-J's historical point is what I was getting at. Control descriptions used to be necessary. They aren't any more. Or at least they shouldn't be!
Regarding the uncrossable fence example, the circle should be centered on the actual side the control is on so that it is possible to tell without reading the descriptions. The description can still be included for the oxygen-deprived runner to double check against, but it should not be necessary to use them in order to know where to find the control.
Relatedly, at one point several years ago I went through and looked at every WOC Sprint Final and found that every control circle was centered such that it wasn't necessary to read the description in order to navigate to it correctly. That's not to say that someone couldn't still screw it up at speed/stress or be saved by reading the description, of course... And I haven't checked the past few years, so maybe things have changed. But I think top European event planners have this figured out.
Regarding under/over bridge, I think those kinds of controls can be unnecessarily duplicitous. You can still place a control such that the runner needs to know whether to get up somewhere or down somewhere in order to get to it, but preferably in a spot where there is only one active running level. See the
sprint maps from WOC 2021 for examples of courses in a complex area, with tunnels and multi-level running, where not a single control is placed in a multi-level area. It also looks as if, from the digital/online version, control circles are all centered such that you can navigate to all of them are without reading the descriptions.
#downWithDescriptions