diff --git a/docs/FEATURES.md b/docs/FEATURES.md
index b4477d59c..894dc496e 100644
--- a/docs/FEATURES.md
+++ b/docs/FEATURES.md
@@ -644,7 +644,7 @@
 
 ### 19. Health Validation
 
-**Command:** `/gsd-health [--repair]`
+**Command:** `/gsd-health [--repair] [--backfill]`
 
 **Purpose:** Validate `.planning/` directory integrity and auto-repair issues.
 
@@ -653,7 +653,8 @@
 - REQ-HEALTH-02: System MUST validate configuration consistency
 - REQ-HEALTH-03: System MUST detect orphaned plans without summaries
 - REQ-HEALTH-04: System MUST check phase numbering and roadmap sync
-- REQ-HEALTH-05: `--repair` flag MUST auto-fix recoverable issues
+- REQ-HEALTH-05: `--repair` flag MUST auto-fix recoverable issues except DESTRUCTIVE-risk ones, which it MUST report but never auto-apply
+- REQ-HEALTH-06: `--backfill` flag MUST synthesize missing MILESTONES.md entries from archived milestone snapshots
 
 ---