The AIP has radar minimum charts for use when under radar vectors if the airport has primary radar cover and ATC provides a radar service. ATCs job is to issue you with clearances according to the radar sector minimums and your job is to accept it when you've confirmed you're safe. If the 25nm MSA is 3000ft, then there is no need to check when you can assure that you're within the MSA sector above a safe altitude. If you are cleared to descend below MSA, it is still your responsibility to check that it is safe according to your Minimum Radar Chart, using conventional means (which could include visual identification of geographic features, but most likely through conventional navaids.
ATC, at least in Europe, will frequently vector you to an intercept inside the FAP so therefore a descent below the platform altitude of the procedure must be issued in order to be able to make the approach (otherwise your only other option is to intercept the approach from above which is obviously undesirable, especially on short finals. You have no other option, this may be due to efficient or crap vectoring. The majority of approaches I've flown in EHAM, EKCH, EDDH and perhaps EGPH will vector inside the FAP consistently. Last one I flew in EHAM had me descending to 1200ft in order to intercept the approach due to some squeaky vectoring, it isn't unusual.