my @list = (
    [$sysName, OCTET_STRING, $newname],
    [$sysDescr, OCTET_STRING, $newdescription],
    [$sysContact, OCTET_STRING, $newcontact]
);

for my $item ( @list ) {
    my $result = $snmp_session->set_request( -varbindlist => $item );
    warn "error: @{[$snmp_session->error]}\n" if ! $result;
}