The 404 page contains a link (/UnicodeJsps) that takes me to a working page.

If moving the tools in the root is too hard then a simple index.html might be good enough.

Or maybe a redirect.
https://developer.mozilla.org/en-US/docs/Web/HTTP/Redirections

The page looks something like this:

Error 404 - Not Found.

No context on this server matched or handled this request.

Contexts known to this server are: