diff --git a/web/backend/api/gateway.go b/web/backend/api/gateway.go
index 4bde5ce829..0b040e2871 100644
--- a/web/backend/api/gateway.go
+++ b/web/backend/api/gateway.go
@@ -25,13 +25,14 @@ import (
 
 // gateway holds the state for the managed gateway process.
 var gateway = struct {
-	mu               sync.Mutex
-	cmd              *exec.Cmd
-	owned            bool // true if we started the process, false if we attached to an existing one
-	bootDefaultModel string
-	runtimeStatus    string
-	startupDeadline  time.Time
-	logs             *LogBuffer
+	mu                  sync.Mutex
+	cmd                 *exec.Cmd
+	owned               bool // true if we started the process, false if we attached to an existing one
+	bootDefaultModel    string
+	bootConfigSignature string
+	runtimeStatus       string
+	startupDeadline     time.Time
+	logs                *LogBuffer
 }{
 	runtimeStatus: "stopped",
 	logs:          NewLogBuffer(200),
@@ -177,14 +178,93 @@ func lookupModelConfig(cfg *config.Config, modelName string) *config.ModelConfig
 	return modelCfg
 }
 
-func gatewayRestartRequired(configDefaultModel, bootDefaultModel, gatewayStatus string) bool {
+func computeConfigSignature(cfg *config.Config) string {
+	if cfg == nil {
+		return ""
+	}
+	var parts []string
+	defaultModel := strings.TrimSpace(cfg.Agents.Defaults.GetModelName())
+	if defaultModel != "" {
+		parts = append(parts, "model:"+defaultModel)
+	}
+	toolSignatures := []string{}
+	if cfg.Tools.ReadFile.Enabled {
+		toolSignatures = append(toolSignatures, "read_file")
+	}
+	if cfg.Tools.WriteFile.Enabled {
+		toolSignatures = append(toolSignatures, "write_file")
+	}
+	if cfg.Tools.ListDir.Enabled {
+		toolSignatures = append(toolSignatures, "list_dir")
+	}
+	if cfg.Tools.EditFile.Enabled {
+		toolSignatures = append(toolSignatures, "edit_file")
+	}
+	if cfg.Tools.AppendFile.Enabled {
+		toolSignatures = append(toolSignatures, "append_file")
+	}
+	if cfg.Tools.Exec.Enabled {
+		toolSignatures = append(toolSignatures, "exec")
+	}
+	if cfg.Tools.Cron.Enabled {
+		toolSignatures = append(toolSignatures, "cron")
+	}
+	if cfg.Tools.Web.Enabled {
+		toolSignatures = append(toolSignatures, "web")
+	}
+	if cfg.Tools.WebFetch.Enabled {
+		toolSignatures = append(toolSignatures, "web_fetch")
+	}
+	if cfg.Tools.Message.Enabled {
+		toolSignatures = append(toolSignatures, "message")
+	}
+	if cfg.Tools.SendFile.Enabled {
+		toolSignatures = append(toolSignatures, "send_file")
+	}
+	if cfg.Tools.FindSkills.Enabled {
+		toolSignatures = append(toolSignatures, "find_skills")
+	}
+	if cfg.Tools.InstallSkill.Enabled {
+		toolSignatures = append(toolSignatures, "install_skill")
+	}
+	if cfg.Tools.Spawn.Enabled {
+		toolSignatures = append(toolSignatures, "spawn")
+	}
+	if cfg.Tools.SpawnStatus.Enabled {
+		toolSignatures = append(toolSignatures, "spawn_status")
+	}
+	if cfg.Tools.I2C.Enabled {
+		toolSignatures = append(toolSignatures, "i2c")
+	}
+	if cfg.Tools.SPI.Enabled {
+		toolSignatures = append(toolSignatures, "spi")
+	}
+	if cfg.Tools.MCP.Enabled {
+		toolSignatures = append(toolSignatures, "mcp")
+	}
+	if cfg.Tools.MCP.Discovery.Enabled {
+		toolSignatures = append(toolSignatures, "mcp_discovery")
+	}
+	if cfg.Tools.MCP.Discovery.UseRegex {
+		toolSignatures = append(toolSignatures, "mcp_discovery_regex")
+	}
+	if cfg.Tools.MCP.Discovery.UseBM25 {
+		toolSignatures = append(toolSignatures, "mcp_discovery_bm25")
+	}
+	if len(toolSignatures) > 0 {
+		parts = append(parts, "tools:"+strings.Join(toolSignatures, ","))
+	}
+	return strings.Join(parts, ";")
+}
+
+func gatewayRestartRequiredBySignature(bootSignature, currentSignature, gatewayStatus string) bool {
 	if gatewayStatus != "running" {
 		return false
 	}
-	if strings.TrimSpace(configDefaultModel) == "" || strings.TrimSpace(bootDefaultModel) == "" {
+	if bootSignature == "" || currentSignature == "" {
 		return false
 	}
-	return configDefaultModel != bootDefaultModel
+	return bootSignature != currentSignature
 }
 
 func isCmdProcessAliveLocked(cmd *exec.Cmd) bool {
@@ -228,10 +308,11 @@ func attachToGatewayProcessLocked(pid int, cfg *config.Config) error {
 	gateway.owned = false // We didn't start this process
 	setGatewayRuntimeStatusLocked("running")
 
-	// Update bootDefaultModel from config
+	// Update bootDefaultModel and bootConfigSignature from config
 	if cfg != nil {
 		defaultModelName := strings.TrimSpace(cfg.Agents.Defaults.GetModelName())
 		gateway.bootDefaultModel = defaultModelName
+		gateway.bootConfigSignature = computeConfigSignature(cfg)
 	}
 
 	logger.InfoC("gateway", fmt.Sprintf("Attached to gateway process (PID: %d)", pid))
@@ -419,6 +500,7 @@ func (h *Handler) startGatewayLocked(initialStatus string, existingPid int) (int
 	gateway.cmd = cmd
 	gateway.owned = true // We started this process
 	gateway.bootDefaultModel = defaultModelName
+	gateway.bootConfigSignature = computeConfigSignature(cfg)
 	setGatewayRuntimeStatusLocked(initialStatus)
 	pid = cmd.Process.Pid
 	logger.InfoC("gateway", fmt.Sprintf("Started picoclaw gateway (PID: %d) from %s", pid, execPath))
@@ -439,6 +521,7 @@ func (h *Handler) startGatewayLocked(initialStatus string, existingPid int) (int
 		if gateway.cmd == cmd {
 			gateway.cmd = nil
 			gateway.bootDefaultModel = ""
+			gateway.bootConfigSignature = ""
 			if gateway.runtimeStatus != "restarting" {
 				setGatewayRuntimeStatusLocked("stopped")
 			}
@@ -713,7 +796,7 @@ func (h *Handler) handleGatewayStatus(w http.ResponseWriter, r *http.Request) {
 
 func (h *Handler) gatewayStatusData() map[string]any {
 	data := map[string]any{}
-	configDefaultModel := ""
+	var configDefaultModel string
 	cfg, cfgErr := config.LoadConfig(h.configPath)
 	if cfgErr == nil && cfg != nil {
 		configDefaultModel = strings.TrimSpace(cfg.Agents.Defaults.GetModelName())
@@ -784,11 +867,14 @@ func (h *Handler) gatewayStatusData() map[string]any {
 		}
 	}
 
-	bootDefaultModel, _ := data["boot_default_model"].(string)
 	gatewayStatus, _ := data["gateway_status"].(string)
-	data["gateway_restart_required"] = gatewayRestartRequired(
-		configDefaultModel,
-		bootDefaultModel,
+	currentConfigSignature := computeConfigSignature(cfg)
+	gateway.mu.Lock()
+	bootConfigSignature := gateway.bootConfigSignature
+	gateway.mu.Unlock()
+	data["gateway_restart_required"] = gatewayRestartRequiredBySignature(
+		bootConfigSignature,
+		currentConfigSignature,
 		gatewayStatus,
 	)
 
diff --git a/web/backend/api/gateway_test.go b/web/backend/api/gateway_test.go
index a5ba2bad27..42f0ab66ce 100644
--- a/web/backend/api/gateway_test.go
+++ b/web/backend/api/gateway_test.go
@@ -77,6 +77,7 @@ func resetGatewayTestState(t *testing.T) {
 		gateway.mu.Lock()
 		gateway.cmd = nil
 		gateway.bootDefaultModel = ""
+		gateway.bootConfigSignature = ""
 		setGatewayRuntimeStatusLocked("stopped")
 		gateway.mu.Unlock()
 	})
@@ -502,9 +503,11 @@ func TestGatewayStatusRequiresRestartAfterDefaultModelChange(t *testing.T) {
 		t.Fatalf("FindProcess() error = %v", err)
 	}
 
+	bootSignature := computeConfigSignature(cfg)
 	gateway.mu.Lock()
 	gateway.cmd = &exec.Cmd{Process: process}
 	gateway.bootDefaultModel = cfg.ModelList[0].ModelName
+	gateway.bootConfigSignature = bootSignature
 	setGatewayRuntimeStatusLocked("running")
 	gateway.mu.Unlock()
 
@@ -548,6 +551,188 @@ func TestGatewayStatusRequiresRestartAfterDefaultModelChange(t *testing.T) {
 	}
 }
 
+func TestGatewayStatusRequiresRestartAfterToolChange(t *testing.T) {
+	resetGatewayTestState(t)
+
+	configPath := filepath.Join(t.TempDir(), "config.json")
+	cfg := config.DefaultConfig()
+	cfg.Agents.Defaults.ModelName = cfg.ModelList[0].ModelName
+	cfg.ModelList[0].SetAPIKey("test-key")
+	cfg.Tools.WriteFile.Enabled = true
+	if err := config.SaveConfig(configPath, cfg); err != nil {
+		t.Fatalf("SaveConfig() error = %v", err)
+	}
+
+	h := NewHandler(configPath)
+	mux := http.NewServeMux()
+	h.RegisterRoutes(mux)
+
+	process, err := os.FindProcess(os.Getpid())
+	if err != nil {
+		t.Fatalf("FindProcess() error = %v", err)
+	}
+
+	bootSignature := computeConfigSignature(cfg)
+	gateway.mu.Lock()
+	gateway.cmd = &exec.Cmd{Process: process}
+	gateway.bootDefaultModel = cfg.ModelList[0].ModelName
+	gateway.bootConfigSignature = bootSignature
+	setGatewayRuntimeStatusLocked("running")
+	gateway.mu.Unlock()
+
+	updatedCfg, err := config.LoadConfig(configPath)
+	if err != nil {
+		t.Fatalf("LoadConfig() error = %v", err)
+	}
+	updatedCfg.Tools.WriteFile.Enabled = false
+	if err := config.SaveConfig(configPath, updatedCfg); err != nil {
+		t.Fatalf("SaveConfig() error = %v", err)
+	}
+
+	gatewayHealthGet = func(string, time.Duration) (*http.Response, error) {
+		return mockGatewayHealthResponse(http.StatusOK, os.Getpid()), nil
+	}
+
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/api/gateway/status", nil)
+	mux.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want %d", rec.Code, http.StatusOK)
+	}
+
+	var body map[string]any
+	if err := json.Unmarshal(rec.Body.Bytes(), &body); err != nil {
+		t.Fatalf("unmarshal response: %v", err)
+	}
+
+	if got := body["gateway_status"]; got != "running" {
+		t.Fatalf("gateway_status = %#v, want %q", got, "running")
+	}
+	if got := body["gateway_restart_required"]; got != true {
+		t.Fatalf("gateway_restart_required = %#v, want true", got)
+	}
+}
+
+func TestGatewayStatusNoRestartRequiredForNonSensitiveChanges(t *testing.T) {
+	resetGatewayTestState(t)
+
+	configPath := filepath.Join(t.TempDir(), "config.json")
+	cfg := config.DefaultConfig()
+	cfg.Agents.Defaults.ModelName = cfg.ModelList[0].ModelName
+	cfg.ModelList[0].SetAPIKey("test-key")
+	cfg.Agents.Defaults.MaxTokens = 1000
+	if err := config.SaveConfig(configPath, cfg); err != nil {
+		t.Fatalf("SaveConfig() error = %v", err)
+	}
+
+	h := NewHandler(configPath)
+	mux := http.NewServeMux()
+	h.RegisterRoutes(mux)
+
+	process, err := os.FindProcess(os.Getpid())
+	if err != nil {
+		t.Fatalf("FindProcess() error = %v", err)
+	}
+
+	bootSignature := computeConfigSignature(cfg)
+	gateway.mu.Lock()
+	gateway.cmd = &exec.Cmd{Process: process}
+	gateway.bootDefaultModel = cfg.ModelList[0].ModelName
+	gateway.bootConfigSignature = bootSignature
+	setGatewayRuntimeStatusLocked("running")
+	gateway.mu.Unlock()
+
+	updatedCfg, err := config.LoadConfig(configPath)
+	if err != nil {
+		t.Fatalf("LoadConfig() error = %v", err)
+	}
+	updatedCfg.Agents.Defaults.MaxTokens = 2000
+	if err := config.SaveConfig(configPath, updatedCfg); err != nil {
+		t.Fatalf("SaveConfig() error = %v", err)
+	}
+
+	gatewayHealthGet = func(string, time.Duration) (*http.Response, error) {
+		return mockGatewayHealthResponse(http.StatusOK, os.Getpid()), nil
+	}
+
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/api/gateway/status", nil)
+	mux.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want %d", rec.Code, http.StatusOK)
+	}
+
+	var body map[string]any
+	if err := json.Unmarshal(rec.Body.Bytes(), &body); err != nil {
+		t.Fatalf("unmarshal response: %v", err)
+	}
+
+	if got := body["gateway_status"]; got != "running" {
+		t.Fatalf("gateway_status = %#v, want %q", got, "running")
+	}
+	if got := body["gateway_restart_required"]; got != false {
+		t.Fatalf("gateway_restart_required = %#v, want false", got)
+	}
+}
+
+func TestGatewayStatusNoRestartRequiredWhenNotRunning(t *testing.T) {
+	resetGatewayTestState(t)
+
+	configPath := filepath.Join(t.TempDir(), "config.json")
+	cfg := config.DefaultConfig()
+	cfg.Agents.Defaults.ModelName = cfg.ModelList[0].ModelName
+	cfg.ModelList[0].SetAPIKey("test-key")
+	if err := config.SaveConfig(configPath, cfg); err != nil {
+		t.Fatalf("SaveConfig() error = %v", err)
+	}
+
+	h := NewHandler(configPath)
+	mux := http.NewServeMux()
+	h.RegisterRoutes(mux)
+
+	gateway.mu.Lock()
+	gateway.cmd = nil
+	gateway.bootDefaultModel = ""
+	gateway.bootConfigSignature = ""
+	setGatewayRuntimeStatusLocked("stopped")
+	gateway.mu.Unlock()
+
+	updatedCfg, err := config.LoadConfig(configPath)
+	if err != nil {
+		t.Fatalf("LoadConfig() error = %v", err)
+	}
+	updatedCfg.Agents.Defaults.ModelName = "different-model"
+	if err := config.SaveConfig(configPath, updatedCfg); err != nil {
+		t.Fatalf("SaveConfig() error = %v", err)
+	}
+
+	gatewayHealthGet = func(string, time.Duration) (*http.Response, error) {
+		return nil, errors.New("no gateway running")
+	}
+
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/api/gateway/status", nil)
+	mux.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want %d", rec.Code, http.StatusOK)
+	}
+
+	var body map[string]any
+	if err := json.Unmarshal(rec.Body.Bytes(), &body); err != nil {
+		t.Fatalf("unmarshal response: %v", err)
+	}
+
+	if got := body["gateway_status"]; got != "stopped" {
+		t.Fatalf("gateway_status = %#v, want %q", got, "stopped")
+	}
+	if got := body["gateway_restart_required"]; got != false {
+		t.Fatalf("gateway_restart_required = %#v, want false", got)
+	}
+}
+
 func TestGatewayStatusReturnsErrorAfterStartupWindowExpires(t *testing.T) {
 	resetGatewayTestState(t)
 
diff --git a/web/frontend/src/components/config/config-page.tsx b/web/frontend/src/components/config/config-page.tsx
index 24a719d863..c3553f5a09 100644
--- a/web/frontend/src/components/config/config-page.tsx
+++ b/web/frontend/src/components/config/config-page.tsx
@@ -32,6 +32,7 @@ import {
 } from "@/components/config/form-model"
 import { PageHeader } from "@/components/page-header"
 import { Button } from "@/components/ui/button"
+import { refreshGatewayState } from "@/store/gateway"
 
 export function ConfigPage() {
   const { t } = useTranslation()
@@ -280,6 +281,7 @@ export function ConfigPage() {
       }
 
       toast.success(t("pages.config.save_success"))
+      void refreshGatewayState({ force: true })
     } catch (err) {
       toast.error(
         err instanceof Error ? err.message : t("pages.config.save_error"),
diff --git a/web/frontend/src/components/config/raw-config-page.tsx b/web/frontend/src/components/config/raw-config-page.tsx
index e40cc73019..56a922fe69 100644
--- a/web/frontend/src/components/config/raw-config-page.tsx
+++ b/web/frontend/src/components/config/raw-config-page.tsx
@@ -19,6 +19,7 @@ import {
 } from "@/components/ui/alert-dialog"
 import { Button } from "@/components/ui/button"
 import { Textarea } from "@/components/ui/textarea"
+import { refreshGatewayState } from "@/store/gateway"
 
 export function RawConfigPage() {
   const { t } = useTranslation()
@@ -56,6 +57,7 @@ export function RawConfigPage() {
       } catch {
         queryClient.invalidateQueries({ queryKey: ["config"] })
       }
+      void refreshGatewayState({ force: true })
     },
     onError: () => {
       toast.error(t("pages.config.save_error"))
diff --git a/web/frontend/src/components/tools/tools-page.tsx b/web/frontend/src/components/tools/tools-page.tsx
index 05aa421221..6a521a5658 100644
--- a/web/frontend/src/components/tools/tools-page.tsx
+++ b/web/frontend/src/components/tools/tools-page.tsx
@@ -14,6 +14,7 @@ import {
   CardTitle,
 } from "@/components/ui/card"
 import { cn } from "@/lib/utils"
+import { refreshGatewayState } from "@/store/gateway"
 
 export function ToolsPage() {
   const { t } = useTranslation()
@@ -33,6 +34,7 @@ export function ToolsPage() {
           : t("pages.agent.tools.disable_success"),
       )
       void queryClient.invalidateQueries({ queryKey: ["tools"] })
+      void refreshGatewayState({ force: true })
     },
     onError: (err) => {
       toast.error(
diff --git a/web/frontend/src/i18n/locales/en.json b/web/frontend/src/i18n/locales/en.json
index 8e051f42eb..3cdacbeee9 100644
--- a/web/frontend/src/i18n/locales/en.json
+++ b/web/frontend/src/i18n/locales/en.json
@@ -66,7 +66,7 @@
         "restarting": "Restarting Gateway...",
         "stopping": "Stopping Gateway..."
       },
-      "restartRequired": "Model changes require a gateway restart to take effect."
+      "restartRequired": "Configuration changes require a gateway restart to take effect."
     }
   },
   "common": {
diff --git a/web/frontend/src/i18n/locales/zh.json b/web/frontend/src/i18n/locales/zh.json
index a6c588807c..22d64a1902 100644
--- a/web/frontend/src/i18n/locales/zh.json
+++ b/web/frontend/src/i18n/locales/zh.json
@@ -66,7 +66,7 @@
         "restarting": "服务重启中...",
         "stopping": "服务停止中..."
       },
-      "restartRequired": "切换默认模型后需要重启服务才能生效。"
+      "restartRequired": "配置变更后需要重启服务才能生效。"
     }
   },
   "common": {