Tokens are your cost and your latency, so treat the context window as a budget you spend. Every prompting choice you just made has a price: few-shot examples, long system prompts, and verbose outputs all cost tokens on every single call, and at scale that is real money and real latency.

This lesson makes cost legible - you read the tokens-used your endpoint returns and connect it directly to the choices in your prompt, so you design with the budget in mind rather than discovering the bill later.