Hello,
This series of messages appeared suddenly.
All at the same time.
It’s already happened to me two or three times during this gaming session.
I often get this in relation to the glassmakers, one line for each worker.
I get the same spam messages for both the glass maker and paper maker. It seems the game reports the message for each worker who does not have a tool. For other work areas that use tools I get the single generic message that some workers do not have enough tools.
I think you are correct to report it as a bug, since tool using locations other than the glass maker and paper maker do not spam the message.