more guidance for the client

Author: paulbastian

draft-ietf-oauth-attestation-based-client-auth.md

@@ -580,7 +580,7 @@ The approach using a challenge explicitly provided by the Authorization Server g
 
 ## Authorization Server Metadata
 
-The Authorization Server SHOULD communicate support and requirement for authentication with Attestation-Based Client Authentication by using the value `attest_jwt_client_auth` in the `token_endpoint_auth_methods_supported` within its published metadata.
+The Authorization Server SHOULD communicate support and requirement for authentication with Attestation-Based Client Authentication by using the value `attest_jwt_client_auth` in the `token_endpoint_auth_methods_supported` within its published metadata. The client SHOULD fetch and parse the Authorization Server metadata and recognize the requirement the requirement for client authentication using Attestation-Based Client Authentication if the given parameters are present.
 
 The Authorization Server SHOULD communicate supported algorithms for client attestations by using `client_attestation_signing_alg_values_supported` and `client_attestation_pop_signing_alg_values_supported` within its published metadata. This enables the client to validate that its client attestation is understood by the Authorization Server prior to authentication. The client MAY try to get a new client attestation with different algorithms.