Great google results with no meta tags - should i add them?

[HeavyLifting]

i own a small information site that gets google first position for certain keyword searches. the person who developed it did not put any meta tags in. is there any chance i could hurt my positioning by adding meta tags, assuming i add relevant keywords and description?

[zangief]

Google does not give much weight to meta tags cause they were abused a lot before.But if there is no description adding relevant meta tags would help.

[dnalias]

add them, it takes 15 mintues and can't hurt.