How to customize GitLab Duo Agent Platform

This post details customization options for the GitLab Duo Agent Platform, including user-level and project-level custom rules defined in `.gitlab/duo/chat-rules.md`, AGENTS.md files for project context at user, project, and subdirectory levels, custom review instructions defined in `.gitlab/duo/mr-review-instructions.yaml` for AI-powered code reviews, and agent skills defined via `SKILL.md` files. It also mentions MCP configuration and custom agents/flows as customization methods.