diff --git a/freqtrade/pairlist/IPairList.py b/freqtrade/pairlist/IPairList.py
index 0a291fdf7..f48a7dcfd 100644
--- a/freqtrade/pairlist/IPairList.py
+++ b/freqtrade/pairlist/IPairList.py
@@ -93,7 +93,15 @@ class IPairList(ABC):
 
     def gen_pairlist(self, cached_pairlist: List[str], tickers: Dict) -> List[str]:
         """
-        Generate the pairlist
+        Generate the pairlist.
+
+        This method is called once by the pairlistmanager in the refresh_pairlist()
+        method to supply the starting pairlist for the chain of the Pairlist Handlers.
+        Pairlist Filters (those Pairlist Handlers that cannot be used at the first
+        position in the chain) shall not override this base implementation --
+        it will raise the exception if a Pairlist Handler is used at the first
+        position in the chain.
+
         :param cached_pairlist: Previously generated pairlist (cached)
         :param tickers: Tickers (from exchange.get_tickers()).
         :return: List of pairs