Your plan gives you one weekly usage pool, shared across Grok Bot, the Grok apps and Cursor. Work is measured in agent steps and tokens, not messages, and Super and Ultra get bigger pools than Premium. xAI doesn't publish the pool's size or a cost per task.
When the pool runs out, the Bot stops until your allowance resets, unless you've added prepaid credit. Auto Top-up stays off unless you turn it on, and a monthly cap limits paid usage.
Routines are where usage disappears. Every run spends usage, even a run that finds nothing to do, and Cursor's own help page warns that an hourly schedule, a short interval or a Slack trigger on a busy channel can use a week of usage in a day. The arithmetic is simple: a weekday-morning routine runs 5 times a week, a daily one 7, an hourly one 168, and every 15 minutes is 672.