Analysis Function to Filter for Different Inputs

I would like a Analysis function that allows for evaluating an attribute to see if the attribute has "bad" data or just has no incoming data. Mostly this is used for the existence of PI Tags. For an input of 'No Tag' I would want the function to output 'No Tag' as both a state and a string to be used as a filter for additional steps in an analysis. If the attribute has a tag but the input is "bad" then it would output something else (like "Bad Value"). Currently, it seems the Analyses will treat both of these inputs as "No Data" for the purposes of the Analysis and for displaying on PI Vision.

In our AF DB we are managing resources that may or may not have PI Tags for certain attributes. We template the attributes and run Analyses using those attributes. The problem we find is that when resources without the PI Tag for those attributes run through an analysis, we cannot accurately handle the instances where there is no tag versus when the data is just bad.