---format=sexp) and the multipart/encrypted part will be replaced
-by the decrypted content. Implies --verify.
+--format=sexp) and on successful decryption the multipart/encrypted
+part will be replaced by the decrypted content.
+
+Decryption expects a functioning \fBgpg-agent\fR(1) to provide any
+needed credentials. Without one, the decryption will fail.
+
+Implies --verify.