Some things an app does cost money each time — sending an email, reading a scan, drafting text. A spending limit keeps that cost predictable. The trick is setting it so it protects you without getting in the way.
Split the work into two piles
Not every action costs the same, and not every action is equally important. Start by sorting the work into two piles: the things that must always happen, and the things that are helpful but optional.
Saving a record or checking who is allowed in usually costs nothing and must always work. Drafting a long summary or reading a large batch of scans costs more and can often wait. Knowing which is which is most of the job.
Set the limit to the optional pile
Your limit should cover a normal month of work with a little room to spare. When the limit is reached, the app pauses the optional, paid actions first — not the essential ones.
That way a busy week or a runaway task slows down the extras instead of stopping real work or running up a surprise bill.
What happens at the limit
When paid work pauses, the app can explain what stopped and why. Free parts of the task keep going where they can, so people are not left staring at a broken screen.
You can review what happened and raise the limit if the extra spending was worth it. The choice stays with you, and it is an easy one to make because the numbers are right there.
Review it now and then
A good limit is not set once and forgotten. Check it every so often against what the app actually used. If you are always well under, you have plenty of headroom. If you keep bumping into it, either raise it or look at what is costing the most.