Discovery Providers MUST NOT have a conflict of interest with any of the Service Providers or Users. In general, the discovery and token mapping functions can not be performed by a SP.
Discovery Service MUST implement Well-Known Location (WKL) method of metadata export, see [SAML2meta] section 4.1 "Publication and Resolution via Well-Known Location", p.29, for normative description of this method.
Discovery Service MUST implement Well-Known Location (WKL) method of metadata import, see [SAML2meta] section 4.1 "Publication and Resolution via Well-Known Location", p.29, for normative description of this method. The Import MUST NOT unintentionally lead to a trust relationship.