When it takes more than a few seconds for SQL Elements to connect to a managed server, an action item is raised indicating that the server is slow. A sluggish connection can be very evident to end users and is a tell-tale sign that something may be going wrong on the server. Troubleshooting a slow SQL Server can be an involved process, not all of which can be easily discussed in the course of a single article, but it is a good idea to take a look at the server workload, the network responsiveness, and the underlying subsystems (including disk and virtualization platforms).
SQL Servers may naturally become less responsive under certain predicted loads, and if the issue is short term and expected (such as during a maintenance window) this warning may be safely ignored.