diff --git a/ocrd_calamari/ocrd-tool.json b/ocrd_calamari/ocrd-tool.json
index 5fc5073..637bc72 100644
--- a/ocrd_calamari/ocrd-tool.json
+++ b/ocrd_calamari/ocrd-tool.json
@@ -18,8 +18,14 @@
         "OCR-D-OCR-CALAMARI"
       ],
       "parameters": {
-        "checkpoint": {"type": "string", "format": "file", "cacheable": true},
-        "voter": {"type": "string", "default": "confidence_voter_default_ctc"}
+        "checkpoint": {
+          "description": "The calamari model files (*.ckpt.json)",
+          "type": "string", "format": "file", "cacheable": true
+        },
+        "voter": {
+          "description": "The voting algorithm to use",
+          "type": "string", "default": "confidence_voter_default_ctc"
+        }
       }
     }
   }