Urban rapid development has created poor open spaces and fewer outdoor learning environments for children. This issue highlights the quality design of urban public and open spaces that can significantly help children’s healthy growth and development. The urban plaza is one of the potential urban open spaces that positively affect the development of talent and creativity in children and develop their physical, social, emotional, and cognitive skills. As public art is an encouraging landscape medium, integrating public art in urban plazas can aid substantially in achieving this goal. The lack of a decision support tool for designing inclusive learning environments at urban plazas has persuaded us to develop the children-oriented urban plaza design (COUP) Toolkit. The COUP Toolkit is a universal tool that can aid design professionals and children’s therapists in assessing and evaluating the impact of urban plaza design on children’s skills growth. By applying the analytical hierarchy process (AHP) method, it was found that the Urban Oasis type of urban plaza contributes the most to skills development in children (WAlt.3 = 0.336), compared to other types (i.e., street plaza, corporate foyer, transit foyer, street, and grand public place). The COUP toolkit has 14 features for designing the urban plazas embedding the public art. Applying AHP indicated that performance art (W2.2 = 0.106), interactive instrument art (W2.3 = 0.106), and spatial composition (W1.1 = 0.103) are most vital in the design of a children-oriented urban plaza. The COUP toolkit was validated through a case study, the Musical Swings (i.e., 21 Balancoires) urban plaza in Montreal, Canada. The COUP toolkit is a rating system and proposes four grading labels based on the scores earned during the assessment process: gold, silver, bronze, and not-certified. The COUP toolkit determined that Musical Swings is ranked as silver; hence, it needs minor improvements, particularly in providing fountains (WSMC2.5 = 0.57) and wading pools (WSMC2.6 = 0.60) to create a proper learning environment for children.