diff --git a/utils/bisect b/utils/bisect
index d1b12575e9c..0f9e53afa7f 100755
--- a/utils/bisect
+++ b/utils/bisect
@@ -1,5 +1,17 @@
 #!/usr/bin/env python
-
+#
+# The way you use this is you create a script that takes in as its first
+# argument a count. The script passes into LLVM the count via a command
+# line flag that disables a pass after LLVM has run after the pass has
+# run for count number of times. Then the script invokes a test of some
+# sort and indicates whether LLVM successfully compiled the test via the
+# scripts exit status. Then you invoke bisect as follows:
+#
+# bisect --start=<start_num> --end=<end_num> ./script.sh "%(count)s"
+#
+# And bisect will continually call ./script.sh with various counts using
+# the exit status to determine success and failure.
+#
 import os
 import sys
 import argparse