diff --git a/lua/updateSampleList.lua b/lua/updateSampleList.lua
index 0480f6d7b..8df42373b 100644
--- a/lua/updateSampleList.lua
+++ b/lua/updateSampleList.lua
@@ -1,3 +1,9 @@
+--[[
+-- Updates a list of BAM files to the latest version in the picard aggregation path
+-- Usage:
+--
+-- lua updateSampleList.lua samples.list > updated_samples.list
+ ]]
 function latestVersion(sample)
   local version = tonumber(sample:match("/v(%d+)/"))
   f = io.open(sample)