diff --git a/AGENTS.md b/AGENTS.md
index a800afc..5ef935e 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -46,7 +46,7 @@ App.jsx (router)
 
 ### Error Bar Convention: 90% Intervals
 
-The API returns 95% HPD intervals (`count_lower`, `count_upper`). However, all chart labels and calculations in this app use **90% intervals**. When converting HPD bounds to standard deviations for synthetic draw generation (used in Chart 5's ridgelines), the divisor used is **3.29** (corresponding to z = 1.645 for a two-tailed 90% interval).
+The API returns 95% HPD intervals (`count_lower`, `count_upper`). However, all chart labels and calculations in this app use **90% intervals**. When converting HPD bounds to standard deviations for the synthetic draw generation fallback (used in the ridgeline chart if real draws can't be fetched — see "Real posterior draws via duckdb-wasm" above), the divisor used is **3.29** (corresponding to z = 1.645 for a two-tailed 90% interval).
 
 If you change this convention, update:
 - `RateDensityRidgeline.jsx` — SD calculation (`intervalWidth / 3.29`) and label text