You can easily verify whether an ADFS implementation is working by using a browser and trying to log on:

https://adfs.yourdomain.com/adfs/ls/IdpInitiatedSignon.aspx

Replace adfs.yourdomain.com accordingly.

Note that in 2016, this no longer works unless you re-enable this feature through Powershell:

Set-AdfsProperties -EnableIdpInitiatedSignonPage $true