Tea-leaves are called cnamhóga or duilleoga tae. Too weak tea is called scileagailí or "skilly"; scinc - probably connected with the verb scinceáil = to decant liquid, or anglais - this last one is actually makeshift tea - milk with hot water (in Finnish we call it "hopeatee", silver tea).
Too strong tea is sútramán; and everything needed for making and drinking tea is called na taeghréithre: the teapot (taepat or taephota), the cup (cupa or cupán), the spoon (spúnóg or in Ulster spanóg), the saucer (sásar)...
A mouthful of tea is a scáilléad. And when you add milk to it, you are said to make it grey (tae a liathadh).