diff --git a/.ralph/prd.json b/.ralph/prd.json
index 52753b7..759fc18 100644
--- a/.ralph/prd.json
+++ b/.ralph/prd.json
@@ -61,8 +61,8 @@
         "go build ./... succeeds"
       ],
       "priority": 4,
-      "passes": false,
-      "notes": ""
+      "passes": true,
+      "notes": "isToolConfirmationMessage was already removed in commit 488e7a9. US-005 will complete the migration to ToolResult.Silent."
     },
     {
       "id": "US-005",
diff --git a/.ralph/progress.txt b/.ralph/progress.txt
index e0a332b..364597c 100644
--- a/.ralph/progress.txt
+++ b/.ralph/progress.txt
@@ -6,10 +6,11 @@ Tool 返回值结构化重构 - 将 Tool 接口返回值从 (string, error) 改
 
 ## Progress
 
-### Completed (2/21)
+### Completed (3/21)
 
 - US-001: Add ToolResult struct and helper functions
 - US-002: Modify Tool interface to return *ToolResult
+- US-004: Delete isToolConfirmationMessage function (already removed in commit 488e7a9)
 
 ### In Progress
 
@@ -20,7 +21,7 @@ Tool 返回值结构化重构 - 将 Tool 接口返回值从 (string, error) 改
 | ID | Title | Status | Notes |
 |----|-------|--------|-------|
 | US-003 | Modify ToolRegistry to process ToolResult | Pending | registry.go already updated |
-| US-004 | Delete isToolConfirmationMessage function | Pending | |
+| US-004 | Delete isToolConfirmationMessage function | Completed | Already removed in commit 488e7a9 |
 | US-005 | Update AgentLoop tool result processing logic | Pending | |
 | US-006 | Add AsyncCallback type and AsyncTool interface | Pending | |
 | US-007 | Heartbeat async task execution support | Pending | |