diff --git a/.opencode/agents/tier4-qa.md b/.opencode/agents/tier4-qa.md
index cacc38eb..c391aeb2 100644
--- a/.opencode/agents/tier4-qa.md
+++ b/.opencode/agents/tier4-qa.md
@@ -24,6 +24,8 @@ ONLY output the requested analysis. No pleasantries.
 You operate statelessly. Each analysis starts fresh.
 Do not assume knowledge from previous analyses or sessions.
 
+**However (added 2026-06-27):** the canonical conventions are in the docs. Read `conductor/code_styleguides/data_oriented_design.md` §8.5 and `python.md` §17 BEFORE diagnosing. Many Tier 2 errors stem from LLM default patterns (`dict[str, Any]`, `Optional[T]`, `hasattr()` dispatch, local imports). Knowing the bans helps you identify whether the bug is a pattern violation vs a logic error.
+
 ## Architecture Reference
 
 When analyzing errors, trace data flow through thread domains documented in: