The suggested tags page should only be accessible to users who are authenticated and autoconfirmed. As such, we will need to show a message indicating this to users who are either not logged in, or are logged in but not autoconfirmed.
As discussed with Pam we'll go with the following messages:
Accurate tags make it easier for all Commons users to find images, so please become autoconfirmed, as only autoconfirmed users can use this tool.
Please log in to see this page and start tagging images. Accurate tags make it easier for all Commons users to find images, and your contributions are appreciated.