Claude needs one of three things to get a client identity: dynamic registration, a Client ID Metadata Document, or credentials Anthropic holds for you.
Claude picks CIMD only when your metadata advertises client_id_metadata_document_supported: true and lists "none" in token_endpoint_auth_methods_supported. Miss the second and Claude falls back to
DCR mints a fresh OAuth client on every new connection, so a busy connector fills your identity provider with junk clients.