Given the Russian government has labeled numerous foreign journalists, news organisations, and even Nobel peace prize winners as foreign agents, I'm not sure it's Meduza's word we should be taking with a grain of salt.
Not that I disagree with your broader point.
[1] https://www.thebureauinvestigates.com/stories/2017-01-17/oba...
it depends on the profile of the individual, it makes it more believable than a generic "foreign agent".