Every Identity Provider's metadata will contain an <IDPSSODescriptor> element, which contains multiple pieces of information about the IdP, including:
errorURLprotocolSupportEnumeration<Scope><UIInfo><KeyDescriptor><SingleSignOnService>
Note that errorURL and protocolSupportEnumeration are not elements in the metadata schema. they are, rather, XML attributes in the <IDPSSODescriptor> element. See below.
Example:
For more information, see IdP SSO Settings (IDPSSODescriptor).