Since God’s word is “flawless” and He is a “shield” of protection to us (:5), it would be stupid to strike out on our own with a better idea. This verse offers a warning to “not add to his words.”
There is no other source of wisdom, understanding or insight that can match up with His Word and anything else we try to incorporate will come up short and be false. Such efforts will come up short, will cost us (“he will rebuke you”) and make us look bad (“prove you a liar”).
I don’t believe this verse is anti-science or offers a restricted view of the world. Neither does it suggest that it is wrong to ask questions. It simply reminds us that all truth in the universe will be consistent with God’s Word. Everything that is true and right out there will have a Biblical underpinning.