Best way to generate part of a URL that is just used for visuals/seo

[eluser]Dannymx[/eluser]
What's the best way to create an url like this when the last segment is not present, in this url the last segment is generated by some data pulled from the database:

Code:

example.com/controller/function/id/some-description-just-for-visuals-and-seo

In this case, if the user just enters the id and whatever in the last segment, the page will be loaded anyway (because the result is based in the id segment).

So, what's the best way to ALWAYS get that last segment present?

It is ok if the controller checks if the segment is empty (or incomplete?) and then redirect with the full text in the url?