Reduce MCP token usage

internal/app/timers.go

@@ -561,14 +561,16 @@ func (m *timerManager) TimerList(ownerID string) []mcp.TimerInfo {
 		if t.status != timerStatusPending && t.status != timerStatusPaused {
 			continue
 		}
+		body, bodyTruncated := timerBodyPreview(t.body)
 		info := mcp.TimerInfo{
-			ID:         t.id,
-			Label:      t.label,
-			Body:       t.body,
-			Kind:       string(t.kind),
-			Status:     t.status,
-			OwnerID:    t.ownerID,
-			WatchedIDs: append([]string(nil), t.watched...),
+			ID:            t.id,
+			Label:         t.label,
+			Body:          body,
+			BodyTruncated: bodyTruncated,
+			Kind:          string(t.kind),
+			Status:        t.status,
+			OwnerID:       t.ownerID,
+			WatchedIDs:    append([]string(nil), t.watched...),
 		}
 		if t.status == timerStatusPending && !t.firesAt.IsZero() {
 			info.FiresAtUnixMS = t.firesAt.UnixMilli()
@@ -581,6 +583,14 @@ func (m *timerManager) TimerList(ownerID string) []mcp.TimerInfo {
 	return out
 }
 
+func timerBodyPreview(body string) (string, bool) {
+	const max = 500
+	if len(body) <= max {
+		return body, false
+	}
+	return body[:max], true
+}
+
 // activeForChild returns the nearest pending or paused timer attached
 // to child id (either owned by it or watching it). Used by the sidebar
 // for the "⏱ 12s" indicator. nil when none.