diff --git a/src/agent/tools/cron/cron-tool.ts b/src/agent/tools/cron/cron-tool.ts
index 1d0aa941..650d9121 100644
--- a/src/agent/tools/cron/cron-tool.ts
+++ b/src/agent/tools/cron/cron-tool.ts
@@ -27,7 +27,7 @@ const CronSchema = Type.Object({
     Type.Literal("remove"),
     Type.Literal("run"),
     Type.Literal("logs"),
-  ], { description: "The action to perform" }),
+  ], { description: "The action to perform. Must be one of: status, list, add, update, remove, run, logs" }),
 
   // list filter
   enabled: Type.Optional(Type.Boolean({ description: "Filter by enabled status (for list)" })),
@@ -154,6 +154,8 @@ function parseSchedule(schedule: CronArgs["schedule"]): CronSchedule | { error:
 
 const TOOL_DESCRIPTION = `Create, manage, and execute scheduled tasks (cron jobs).
 
+IMPORTANT: The "action" parameter must be exactly one of these values: "status", "list", "add", "update", "remove", "run", "logs"
+
 ## Actions
 
 ### status