The UPSC evaluates essay papers based on specific criteria, including clarity of thought, coherence, structure, and the ability to articulate arguments effectively. Essays should also demonstrate knowledge of contemporary issues and an understanding of the socio-economic context of national and global matters. Evaluators look for the ability to critically analyze topics and provide well-reasoned conclusions. Language proficiency and adherence to word limits are also assessed, highlighting the importance of effective communication skills in scoring well in essays.