Apple Script Not working

Hi,
Apple Script newbie here:
I have created the following AppleScript and embedded it in a rule:
***
tell script "Slack"
set Workspace to "Lifepuzzle"
set channel to "miscellaneoustasks"
send message "@Abegail new blog or email is uploaded"
end tell
***
When I run it in Coderunner is does exactly what I want it to - DMs a colleague to say that a new blog or email is in the file. Hazel just ignores it. The script is at the end of a rule that moves a file to another folder and sends a notification.
Many thanks.
Apple Script newbie here:
I have created the following AppleScript and embedded it in a rule:
***
tell script "Slack"
set Workspace to "Lifepuzzle"
set channel to "miscellaneoustasks"
send message "@Abegail new blog or email is uploaded"
end tell
***
When I run it in Coderunner is does exactly what I want it to - DMs a colleague to say that a new blog or email is in the file. Hazel just ignores it. The script is at the end of a rule that moves a file to another folder and sends a notification.
Many thanks.