"incisive observation" is correct and usable in written English.
You can use it to refer to a keen observation that allows you to better understand something or reach a conclusion. For example, "Jane's incisive observation about the relationships between the characters revealed a surprising truth."
Woody is never self-pitying; he's always colorful, mixing rueful humor and incisive observation.
In the Guardian, Michael Billington hailed Reza as "a born satirist"; others proclaimed themselves "delighted by her incisive observation" and "shrewd humour".
Then, so help me God, I had to try to play the next one…" Reluctant to enter into the current political fray about arts cuts or music education, he instead makes a typically incisive observation about the musical world at large.
At the time he made the incisive observation that whenever a chemotherapeutic agent succeeds in relieving symptoms, this results in the subjective judgment that it is effective by the patient concerned; the treating clinician, however, must rely on objective criteria to evaluate a drug's efficacy.
(I found myself thinking, by contrast, of recently published stories by the late filmmaker Kathleen Collins, with their incisive observations regarding participants and observers of civil-rights activism).
Incisive observations by a tribally well-born immigrant.
Her talent is for short, provocative statements and incisive observations.
"Ace of Spades" is much more convincing when Matthews demonstrates the provisionality of racial categories through his incisive observations.
Sepia toning gives Kerry Stuart Coppin's street scenes the look of slightly faded prints, tingeing with nostalgia his incisive observations of life in Dakar.
I've always considered Marvin a wonderfully smart actor, and this clip (above), in which he discusses his work with Ford, is a treasure trove of incisive observations.
"There are a lot of acute and incisive observations about sexual attraction and relationships and the slightly darker undercurrents at work".
