What are the minimum required permissions for pg_isready

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/16/app-pg-isready.html
Description:

Hello,

The documentation does not specify what are the minimum required permissions
for setting up pg_isready .
I was wondering if this could be added so devops teams know how to create a
user that is used only for monitoring postgresql. 

I assume this user will need to connect and nothing else ?
I also assume we would need to drop public access for that user ?

Thanks,
Eugen