As a general rule I completely agree.

On the other hand, token bucket implementations are hard to understand and hard to debug. And an ambiguous variable name can cause trouble because some devs might think it "obviously" refers to enough budget for some other slice of requests.

I think my preferred solution here is to extract the condition into a boolean function with a long name like HasBudgetForAllRequests. This solves the long variable name issue and also gives you a useful place to add to your budget computation logic if you need to.