TPEE Toptronic® Prompt Engineering Editor

3. Context Windows and Tokens

Budget prompt size, attachments, and long conversations.

By Jacques Botte, founder of Toptronic®. Last updated 12 September 2026.

The lesson

A token is a small chunk of text. Context window is the model's working memory for the current request.

Long context is useful, but it costs money, time, and memory. Put the highest-value facts first and remove old noise.

For coding, include file names, exact error text, acceptance criteria, and what must not change.

Check yourself

Question 1: What is a context window?
  1. A GPU fan setting
  2. The model working memory for the current request — correct
  3. A Windows desktop panel
  4. A license file

Answer: The model working memory for the current request

The context window is the amount of prompt and conversation the model can consider.

Question 2: Why can very long prompts be expensive or slow?
  1. They use more input tokens and processing — correct
  2. They make the keyboard slower
  3. They disable Markdown
  4. They shrink the model

Answer: They use more input tokens and processing

More tokens usually mean more cost, latency, and attention burden.

Question 3: For coding help, which context is most valuable?
  1. Only the word fix
  2. A random screenshot without explanation
  3. No project details
  4. Exact file paths, errors, constraints, and acceptance criteria — correct

Answer: Exact file paths, errors, constraints, and acceptance criteria

Specific technical context helps the model solve the actual problem.

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