Problem with add_tag

Great !
It's works:
if [tags_tmp][0] =~/SUCC/ {
mutate { add_tag => ["succ"] }
}
if [tags_tmp][0] =~/FAIL/ {
mutate { add_tag => ["fail"] }
}
if [tags_tmp][0] =~/AUTHEN/ {
mutate { add_tag => ["authen"] }
}