sdktool: command not found

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

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

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/sdktool - from package: qt-creator

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/sdktool - from package: qtcreator

You may install the required package with command apt-get install {package}

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