How hard it should think
A short customer text does not need a long think. A messy job does. You pick how much.
The work before the answer
Reasoning is the work the model does before it writes. More of it means the model checks the draft longer. Less of it means a faster answer.
Normal for a plain job
A missed-call text or a quote chase is a plain job. Normal is enough. The draft stays close to the facts you gave.
High for a harder call
High is for a job with a real tradeoff, such as comparing two quotes or finding what a long note left out. Use it when a fast answer would skip a step.
Match the job
Start on Normal. Move to High only when the draft is thin or the job is messy. More thinking does not fill in facts you left out. Those belong in the context you paste.
Try it now
Take a real customer text. Ask for a reply with the fast setting, then again with the setting that thinks longer. Keep the reply that stays closest to the facts you gave.
Copy this prompt
Paste the customer text where the brackets are.
Here is a customer text: [paste it]. Write a short reply I can send. Then list anything you were unsure about. Do not add facts I did not give you.
Now you know
Privacy: Paste the job. Leave out the name, the address, and the card number.