diff --git a/pkg/agent/loop.go b/pkg/agent/loop.go
index 03d5bb7..778d9e1 100644
--- a/pkg/agent/loop.go
+++ b/pkg/agent/loop.go
@@ -350,7 +350,11 @@ func (al *AgentLoop) tryFallbackProviders(ctx context.Context, msg bus.InboundMe
 	lastErr := primaryErr
 	candidates := append([]string(nil), al.providerNames[1:]...)
 	if al.ekg != nil {
-		candidates = al.ekg.RankProviders(candidates)
+		errSig := ""
+		if primaryErr != nil {
+			errSig = primaryErr.Error()
+		}
+		candidates = al.ekg.RankProvidersForError(candidates, errSig)
 	}
 	for _, name := range candidates {
 		p, ok := al.providerPool[name]
@@ -361,11 +365,13 @@ func (al *AgentLoop) tryFallbackProviders(ctx context.Context, msg bus.InboundMe
 		if al.ekg != nil {
 			st := "success"
 			lg := "fallback provider success"
+			errSig := ""
 			if err != nil {
 				st = "error"
 				lg = err.Error()
+				errSig = err.Error()
 			}
-			al.ekg.Record(ekg.Event{Session: msg.SessionKey, Channel: msg.Channel, Source: "provider_fallback", Status: st, Provider: name, Model: al.model, Log: lg})
+			al.ekg.Record(ekg.Event{Session: msg.SessionKey, Channel: msg.Channel, Source: "provider_fallback", Status: st, Provider: name, Model: al.model, ErrSig: errSig, Log: lg})
 		}
 		if err == nil {
 			logger.WarnCF("agent", "LLM fallback provider switched", map[string]interface{}{"provider": name})
diff --git a/pkg/ekg/engine.go b/pkg/ekg/engine.go
index d7ea5ca..9017167 100644
--- a/pkg/ekg/engine.go
+++ b/pkg/ekg/engine.go
@@ -175,9 +175,14 @@ var (
 )
 
 func (e *Engine) RankProviders(candidates []string) []string {
+	return e.RankProvidersForError(candidates, "")
+}
+
+func (e *Engine) RankProvidersForError(candidates []string, errSig string) []string {
 	if len(candidates) <= 1 || e == nil {
 		return append([]string(nil), candidates...)
 	}
+	errSig = NormalizeErrorSignature(errSig)
 	events := e.readRecentEvents()
 	score := map[string]float64{}
 	for _, c := range candidates {
@@ -191,13 +196,22 @@ func (e *Engine) RankProviders(candidates []string) []string {
 		if _, ok := score[p]; !ok {
 			continue
 		}
+		weight := 1.0
+		evSig := NormalizeErrorSignature(ev.ErrSig)
+		if errSig != "" {
+			if evSig == errSig {
+				weight = 2.5
+			} else if evSig != "" {
+				weight = 0.4
+			}
+		}
 		switch strings.ToLower(strings.TrimSpace(ev.Status)) {
 		case "success":
-			score[p] += 1.0
+			score[p] += 1.0 * weight
 		case "suppressed":
-			score[p] += 0.2
+			score[p] += 0.2 * weight
 		case "error":
-			score[p] -= 1.0
+			score[p] -= 1.0 * weight
 		}
 	}
 	ordered := append([]string(nil), candidates...)