A seek requires a predicate. A seek is a navigation of an index looking for a value or the start/end of a range. If there's no predicate (as in SELECT TOP 1 FROM Table), then you can't have a seek.
iirc there's definitions somewhere on my blog. Try the search box or google, I don't remember where it would be. Probably in one of my indexing posts.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability