I'm looking for the word that says there's such a thing as using too much description

Solution 1:

There's a such thing as "verbosity."

verbosity

the state or quality of being verbose; superfluity of words; wordiness

Also, using too many adjectives is termed "purple prose" or "flowery language."

purple prose

prose that is too elaborate or ornate.

If the words actually add no meaning, then the term is "deadwood."

deadwood

(in writing) unnecessary words, phrases, or exposition; expendable verbiage.

Ironic, though, that you're criticizing this person for having too many words when you yourself don't have enough. But you're right about using too many adjectives. It makes for terrible writing. So tedious.

Solution 2:

and now from the OED: a noun!

TMI n. colloquial (originally in the language of electronic communications) too much information; usually implying disgust or disapproval in response to a disclosure of an excessively personal or graphic nature.

As in:

1996 Lemonade & Pizza in alt.cosuard (Usenet newsgroup) 25 Mar.
All the underwear in question is briefs and not boxers. TMI?

Information overload (1967) was and still is used, but the OED added TMI as a noun in 2009.