I don't know how to optimally use the search feature on this site

Do some cards not have their text tagged in the database? Let's say I'm a dummy who doesn't know how to look up cards from the most recent set elsewhere, and I want to "that neutral Protoss minion". I search "costs (0)" and find many cards with that in the text, but not Void Ray. I tried searching other combinations of keywords in Void Ray's text and couldn't find it. If I search the name of the card, that works just fine.

Also we can't search by card type? I get this is a bug report and not a feature request, but I assume there are more filters that can be put on the advanced search function.

Great feedback. I can find  Void Ray  when I search "costs (0)" with the expansion set but without the expansion it doesn't appear. This is most definitely a bug. I'll fix this!

I'll also add some more filters while I am at it, card type is a great candidate. I'll ping Alan about it too just in-case this turns out to be a different issue. 

EDIT: Looks like Alan has added the minion filter. Maybe also a card type filter (minion, spell, weapon)

Pushed out a new update that now allows you to search by card type. 

For example, you can search "costs (0)" along with filter mech,  Void Ray  now shows up.

https://hearthcard.io/cards/search?search=costs+%280%29&minion_type%5B%5D=17&set_search=&mana_cost=&mode=all&sort=name&direction=asc

I also found Void Ray on page 3 of the results for just "costs (0)". 

Good points brought up though, I want to see what else I can add to make searching easier/more intuitive.