Another thing that can happen is that if your Tag contains more posts than will fit on one page (according to the Options for Blog Reading you have set in the Administration panels of your blog), the Tag archive will split into multiple pages. And maybe you only want to display your static text if the viewer is on the first page of results, or you want to display different text for the other pages.
To make this happen, you can use a PHP if statement, which looks at the value of the $paged WordPress variable ($paged is equal to the page number: 1 for the first page of results, 2 for the second page, etc.). It may sound complicated, but it’s actually not too bad. Just put the following above