diff --git a/tools/cronjob_tools.py b/tools/cronjob_tools.py
index ada4e4af0065..b0a918231eb5 100644
--- a/tools/cronjob_tools.py
+++ b/tools/cronjob_tools.py
@@ -712,11 +712,11 @@ def cronjob(
             },
             "prompt": {
                 "type": "string",
-                "description": "For create: the full self-contained prompt. If skills are also provided, this becomes the task instruction paired with those skills."
+                "description": "REQUIRED for action=create (unless no_agent=True or script is set). The full self-contained prompt. If skills are also provided, this becomes the task instruction paired with those skills."
             },
             "schedule": {
                 "type": "string",
-                "description": "REQUIRED for action=create. For create/update: '30m', 'every 2h', '0 9 * * *', or ISO timestamp. Examples: '30m' (every 30 minutes), 'every 2h' (every 2 hours), '0 9 * * *' (daily at 9am), '2026-06-01T09:00:00' (one-shot). You MUST include this field when action=create."
+                "description": "REQUIRED for action=create. You MUST always include this parameter if action=create. For create/update: '30m', 'every 2h', '0 9 * * *', or ISO timestamp. Examples: '30m' (every 30 minutes), 'every 2h' (every 2 hours), '0 9 * * *' (daily at 9am), '2026-06-01T09:00:00' (one-shot)."
             },
             "name": {
                 "type": "string",