Can you elaborate what do you mean by COOL,CHILL? Are you a customer or a provider or health insurance?

Generally, these are the characteristics of a good health insurance plan

1. No Room rent or ICU limit
2. No co-payments
3. No disease specific sub-limits
4. Longer Pre and Post hospitalization duration
5. AYUSH/Alternate treatment covered upto SI
6. In-built or rider which cover non-payable/non-medical items
7. In-built or rider for inflation protect
8. Good max NCB limit
9. Restoration on partial exhaustion which also covers same illness.
10. Good customer service and track record

It's also important to have sufficient coverage as per your requirement.

Do check the articles on https://www.beshak.org/insurance/health-insurance/ to understand more.