When I've previously checked such automatic insurances, the levels of cover were fairly low. What level of cover does it offer for medical expenses? For repatriation costs?
Some credit card insurance will also only cover eventualities arising while travelling to and from the destination and not while actually located there. Best to check the terms & conditions to make sure that you don't need additional holiday/travel insurance cover. Such cover is relatively cheap these days (especially for annual multi-trip policies) so don't scrimp on it if it would leave you exposed to risk.
Check out the holiday insurance thread in the key topics post and search for previous holiday/travel insurance threads that might be of interest to you. Several online insurance providers/resellers make policy documents/terms & conditions available for comparison before purchase.
You need to check the terms & conditions of the policy document and compare it to other policies on offer. Different people have different insurance cover needs/wants so it's impossible to say if it's suitable for your situation.