I am hard coding through Eclipse. game

I am compiling and hard coding through Eclipse. I am modifying a game called Lineage using Java, and GPT 5.2 has a lot of manuals. Please recommend GPT5.2, which is suitable for hard coding for use as a search engine. I am currently using Ultraplan.

안녕하세요 답변감사합니다 여기서제일 하드코딩에적합한 gpt는 어떤것일지 답변주실수있으신가요?

Always Plan mode, i recomended using GPT 5.2 High / xHight for complex and execute with GPT-5.2 Codex. its better for execution.

check this best practice from cursor about agent