src/Tools/VSCode/extension/package.json

                 "isabelle.home": {
                     "type": "string",
                     "default": "",
                     "description": "ISABELLE_HOME directory"
                 },
-                "isabelle.arguments": {
+                "isabelle.args": {
                     "type": "array",
                     "items": { "type": "string" },
                     "default": [],
                     "description": "command-line arguments for isabelle vscode_server"
                 }