eulb-describe-tags: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/eulb-describe-tags - from package: euca2ools

You may install the required package with command yum install {package}
Error in other languages:
eulb-describe-tags: bevel nie gevind nie
eulb-describe-tags: comandă negăsită
eulb-describe-tags: comando não encontrado
eulb-describe-tags: commande introuvable
eulb-describe-tags: command not found
eulb-describe-tags: käsku ei ole
eulb-describe-tags: không tìm thấy lệnh
eulb-describe-tags: komanda nerasta
eulb-describe-tags: Kommando nicht gefunden.
eulb-describe-tags: kommandot finns inte
eulb-describe-tags: komut yok
eulb-describe-tags: nie znaleziono polecenia
eulb-describe-tags: níor aimsíodh an t-ordú
eulb-describe-tags: no se encontró la orden
eulb-describe-tags: no s'ha trobat l'ordre
eulb-describe-tags: opdracht niet gevonden
eulb-describe-tags: parancs nem található
eulb-describe-tags: perintah tidak ditemukan
eulb-describe-tags: príkaz nenájdený
eulb-describe-tags: příkaz nenalezen
eulb-describe-tags: команда не найдена
eulb-describe-tags: командата не е открита
eulb-describe-tags: 命令找不到
eulb-describe-tags: コマンドが見つかりません