na-adjective, noun which may take the genitive case particle 'no'
too good; overly excellent
Used when something is excessively good, often implying it is suspicious or too perfect for the context, such as a child's work or a story.
この作文は小学生が書いたにしては出来過ぎだ。
This essay is too good for an elementary school student to have written.
話が出来過ぎていて、信じられない。
The story is too perfect to be true.
noun
overproduction; making too much
Refers to producing an excessive amount, often used for crops or manufactured goods.
今年は野菜が出来過ぎて、値段が下がった。
This year, vegetables were overproduced and prices fell.
商品の出来過ぎで在庫が余っている。
Due to overproduction of goods, we have excess inventory.
Compound of 出来 (deki, 'result, production') and 過ぎ (sugi, 'excess'). The meaning 'too good' likely developed from the idea of a result exceeding expectations.