In March 2012, expanded URL enrichment was introduced. Prior to this time, Tweet payloads included only the user-provided URL. Therefore, if the user included a shortened URL, it can be difficult to match the (expanded) URLs of interest. With both the Historical PowerTrack and the Search APIs, this metadata is available as of March 2012.
In July 2016, Enhanced URL Enrichment was introduced. This improved version provides the HTML title and description of a website in the Tweet payload, along with operators to match those. With Historical PowerTrack, this metadata will be available in July 2016. With the Search APIs, this metadata will start appearing in December 2014.
In September 2016, Twitter introduced ‘native attachments’ where a final shared link is not counted towards the 140 character Tweet limit. Both URL enrichments still apply to these shared links.