diff --git a/swh/indexer/cli.py b/swh/indexer/cli.py
--- a/swh/indexer/cli.py
+++ b/swh/indexer/cli.py
@@ -97,7 +97,7 @@
 @click.argument("mapping-name")
 @click.argument("file", type=click.File("rb"))
 def mapping_translate(mapping_name, file):
-    """Prints the list of known mappings."""
+    """Translates file from mapping-name to codemeta format."""
     import json
 
     from swh.indexer import metadata_dictionary