I am sure there is a word—I've seen it somewhere before and it's not one of those obscene words on tumblr. It means someone who chooses their words thoughtfully.
It's not an adjective but a noun to name the person, and it's not "wordsmith".
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The word erudite exists as a noun, though it is said by the OED to be rare.
[So French érudit.] An erudite person, a scholar. rare.
1865 G. Grote Plato I. iv. 141 These laborious and useful erudites.
1888 Pall Mall Gaz. 6 Sept. 3/1 There are to be found, in and out of America, women citizens of that great country..female would-be erudites.
So I believe the word you need is erudite. Tom is an erudite
Unfortunately articulate does not similarly exist as a noun. The best the OED offers is articulate-speaking person - see examples below.
1829 T. Carlyle in Foreign Rev. 3 98 Were not these Plays translated almost into every language of articulate-speaking men.
1931 Amer. Lit. 3 79 ‘To make poems’, is, as Mr. Kuhl says, ‘a heart cry such as rarely is uttered by an articulate-speaking person.’
1994 M. A. Perkins Coleridge's Philos. (1999) i. 44
Articulate by itself does not exist as a noun in the way erudite does - though it does have a zoological sense!