diff --git a/internal/ai/runtime/executor/tooling.go b/internal/ai/runtime/executor/tooling.go
index e3b1d14..709e1f3 100644
--- a/internal/ai/runtime/executor/tooling.go
+++ b/internal/ai/runtime/executor/tooling.go
@@ -93,7 +93,6 @@ func toolSetStaticToolMetadata(toolSet *registry.ToolSet) map[string]registry.To
 		item.ToolCode = strings.TrimSpace(item.ToolCode)
 		item.ServerCode = strings.TrimSpace(item.ServerCode)
 		item.ToolName = strings.TrimSpace(item.ToolName)
-		item.SourceType = strings.TrimSpace(item.SourceType)
 		ret[trimmedName] = item
 	}
 	return ret
diff --git a/internal/ai/runtime/internal/impl/callbacks/agent_trace_handler.go b/internal/ai/runtime/internal/impl/callbacks/agent_trace_handler.go
index 15f6fb0..1c7e0f4 100644
--- a/internal/ai/runtime/internal/impl/callbacks/agent_trace_handler.go
+++ b/internal/ai/runtime/internal/impl/callbacks/agent_trace_handler.go
@@ -7,6 +7,7 @@ import (
 	"time"
 
 	impladapter "cs-agent/internal/ai/runtime/internal/impl/adapter"
+	"cs-agent/internal/pkg/enums"
 	"cs-agent/internal/pkg/toolx"
 
 	einotool "github.com/cloudwego/eino/components/tool"
@@ -18,7 +19,7 @@ type ToolMetadata struct {
 	ToolCode   string
 	ServerCode string
 	ToolName   string
-	SourceType string
+	SourceType enums.ToolSourceType
 }
 
 type RuntimeTraceHandler struct {
@@ -101,7 +102,7 @@ func (h *RuntimeTraceHandler) WrapInvokableToolCall(_ context.Context, endpoint
 			item.ErrorMessage = err.Error()
 		}
 		h.collector.AddToolItem(item)
-		if metadata, ok := h.resolveToolMetadata(item.ToolName); ok && strings.TrimSpace(metadata.SourceType) == toolx.GraphCreateTicketConfirm.ServerCode {
+		if metadata, ok := h.resolveToolMetadata(item.ToolName); ok && metadata.SourceType == enums.ToolSourceTypeGraph {
 			recommendedAction, riskLevel, ticketDraftReady := parseGraphToolOutcome(item.ToolCode, result)
 			h.collector.AddGraphToolItem(GraphToolTraceItem{
 				ToolCode:          item.ToolCode,
diff --git a/internal/ai/runtime/internal/impl/factory/tool_factory.go b/internal/ai/runtime/internal/impl/factory/tool_factory.go
index 1d32139..79005ee 100644
--- a/internal/ai/runtime/internal/impl/factory/tool_factory.go
+++ b/internal/ai/runtime/internal/impl/factory/tool_factory.go
@@ -8,6 +8,7 @@ import (
 	impladapter "cs-agent/internal/ai/runtime/internal/impl/adapter"
 	runtimetooling "cs-agent/internal/ai/runtime/tooling"
 	"cs-agent/internal/models"
+	"cs-agent/internal/pkg/enums"
 	"cs-agent/internal/pkg/toolx"
 
 	einotool "github.com/cloudwego/eino/components/tool"
@@ -34,7 +35,7 @@ func (f *ToolFactory) BuildMCPTools(aiAgent *models.AIAgent) ([]runtimetooling.M
 		if toolCode == "" {
 			toolCode = toolx.BuildMCPToolCode(item.ServerCode, item.ToolName)
 		}
-		if toolx.ResolveToolSourceType(toolCode) != "mcp" {
+		if toolx.ResolveToolSourceType(toolCode) != enums.ToolSourceTypeMCP {
 			continue
 		}
 		serverCode, toolName := toolx.SplitMCPToolCode(toolCode)
diff --git a/internal/ai/runtime/internal/impl/factory/tool_helpers.go b/internal/ai/runtime/internal/impl/factory/tool_helpers.go
index f90d910..e01ef1e 100644
--- a/internal/ai/runtime/internal/impl/factory/tool_helpers.go
+++ b/internal/ai/runtime/internal/impl/factory/tool_helpers.go
@@ -8,6 +8,7 @@ import (
 	"cs-agent/internal/ai/runtime/registry"
 	runtimetooling "cs-agent/internal/ai/runtime/tooling"
 	"cs-agent/internal/models"
+	"cs-agent/internal/pkg/enums"
 	"cs-agent/internal/pkg/toolx"
 )
 
@@ -37,7 +38,7 @@ func buildRuntimeTraceToolMetadata(
 			ToolCode:   strings.TrimSpace(item.ToolCode),
 			ServerCode: strings.TrimSpace(item.ServerCode),
 			ToolName:   strings.TrimSpace(item.ToolName),
-			SourceType: "mcp",
+			SourceType: enums.ToolSourceTypeMCP,
 		}
 	}
 	for modelName, metadata := range staticToolMetadata {
@@ -45,7 +46,6 @@ func buildRuntimeTraceToolMetadata(
 		metadata.ToolCode = strings.TrimSpace(metadata.ToolCode)
 		metadata.ServerCode = strings.TrimSpace(metadata.ServerCode)
 		metadata.ToolName = strings.TrimSpace(metadata.ToolName)
-		metadata.SourceType = strings.TrimSpace(metadata.SourceType)
 		if modelName == "" || metadata.ToolCode == "" {
 			continue
 		}
diff --git a/internal/ai/runtime/registry/registry.go b/internal/ai/runtime/registry/registry.go
index 6eb4fcf..eb83ae6 100644
--- a/internal/ai/runtime/registry/registry.go
+++ b/internal/ai/runtime/registry/registry.go
@@ -60,8 +60,8 @@ func (r *Registry) Resolve(ctx Context) (*ToolSet, error) {
 		if strings.TrimSpace(resolvedMetadata.ToolName) == "" {
 			resolvedMetadata.ToolName = toolName
 		}
-		if strings.TrimSpace(resolvedMetadata.SourceType) == "" {
-			resolvedMetadata.SourceType = strings.TrimSpace(spec.SourceType)
+		if resolvedMetadata.SourceType == "" {
+			resolvedMetadata.SourceType = spec.SourceType
 		}
 		ret.StaticToolMetadata[toolName] = ToolMetadata{
 			ToolCode:   resolvedMetadata.ToolCode,
diff --git a/internal/ai/runtime/registry/types.go b/internal/ai/runtime/registry/types.go
index 198923f..248f128 100644
--- a/internal/ai/runtime/registry/types.go
+++ b/internal/ai/runtime/registry/types.go
@@ -2,6 +2,7 @@ package registry
 
 import (
 	"cs-agent/internal/models"
+	"cs-agent/internal/pkg/enums"
 	"cs-agent/internal/pkg/toolx"
 
 	einotool "github.com/cloudwego/eino/components/tool"
@@ -19,7 +20,7 @@ type ToolMetadata struct {
 	ToolCode   string
 	ServerCode string
 	ToolName   string
-	SourceType string
+	SourceType enums.ToolSourceType
 }
 
 // ToolSet 描述当前运行时可直接挂载到 ToolsNode 上的固定工具集合。
diff --git a/internal/pkg/dto/response/mcp_response.go b/internal/pkg/dto/response/mcp_response.go
index 930e7c8..0580433 100644
--- a/internal/pkg/dto/response/mcp_response.go
+++ b/internal/pkg/dto/response/mcp_response.go
@@ -1,6 +1,9 @@
 package response
 
-import "cs-agent/internal/ai/mcps"
+import (
+	"cs-agent/internal/ai/mcps"
+	"cs-agent/internal/pkg/enums"
+)
 
 type MCPConnectionResponse struct {
 	ServerCode string `json:"serverCode"`
@@ -66,15 +69,15 @@ func BuildMCPToolInfoResponses(items []mcps.ToolInfo) []MCPToolInfoResponse {
 }
 
 type MCPToolCatalogResponse struct {
-	ToolCode     string `json:"toolCode"`
-	ServerCode   string `json:"serverCode"`
-	ToolName     string `json:"toolName"`
-	SourceType   string `json:"sourceType"`
-	AutoInjected bool   `json:"autoInjected"`
-	Title        string `json:"title"`
-	Description  string `json:"description"`
-	InputSchema  any    `json:"inputSchema"`
-	OutputSchema any    `json:"outputSchema,omitempty"`
+	ToolCode     string               `json:"toolCode"`
+	ServerCode   string               `json:"serverCode"`
+	ToolName     string               `json:"toolName"`
+	SourceType   enums.ToolSourceType `json:"sourceType"`
+	AutoInjected bool                 `json:"autoInjected"`
+	Title        string               `json:"title"`
+	Description  string               `json:"description"`
+	InputSchema  any                  `json:"inputSchema"`
+	OutputSchema any                  `json:"outputSchema,omitempty"`
 }
 
 type MCPToolResultContentResponse struct {
diff --git a/internal/pkg/enums/tool.go b/internal/pkg/enums/tool.go
new file mode 100644
index 0000000..bdb4605
--- /dev/null
+++ b/internal/pkg/enums/tool.go
@@ -0,0 +1,24 @@
+package enums
+
+type ToolSourceType string
+
+const (
+	ToolSourceTypeMCP     ToolSourceType = "mcp"
+	ToolSourceTypeGraph   ToolSourceType = "graph"
+	ToolSourceTypeBuiltin ToolSourceType = "builtin"
+)
+
+var ToolSourceTypeValues = []ToolSourceType{
+	ToolSourceTypeMCP,
+	ToolSourceTypeGraph,
+	ToolSourceTypeBuiltin,
+}
+
+func IsValidToolSourceType(sourceType ToolSourceType) bool {
+	for _, item := range ToolSourceTypeValues {
+		if item == sourceType {
+			return true
+		}
+	}
+	return false
+}
diff --git a/internal/pkg/toolx/builtin_tools.go b/internal/pkg/toolx/builtin_tools.go
index 67f643f..06c5fd8 100644
--- a/internal/pkg/toolx/builtin_tools.go
+++ b/internal/pkg/toolx/builtin_tools.go
@@ -1,6 +1,10 @@
 package toolx
 
-import "strings"
+import (
+	"strings"
+
+	"cs-agent/internal/pkg/enums"
+)
 
 type ToolSpec struct {
 	Code          string
@@ -8,7 +12,7 @@ type ToolSpec struct {
 	Name          string
 	Title         string
 	Description   string
-	SourceType    string
+	SourceType    enums.ToolSourceType
 	AutoInjected  bool
 	DirectAccess  bool
 	RuntimeStatic bool
@@ -20,7 +24,7 @@ type ToolMetadata struct {
 	ToolCode   string
 	ServerCode string
 	ToolName   string
-	SourceType string
+	SourceType enums.ToolSourceType
 }
 
 var (
@@ -30,7 +34,7 @@ var (
 		Name:         "tool_search",
 		Title:        "搜索并调用动态工具",
 		Description:  "用于搜索当前允许使用的 MCP 工具，并在确认目标 toolCode 后动态调用该工具。适合处理长尾工具，不应替代固定内置流程工具。",
-		SourceType:   "builtin",
+		SourceType:   enums.ToolSourceTypeBuiltin,
 		AutoInjected: true,
 		DirectAccess: true,
 		Appendix: strings.TrimSpace(`
@@ -46,7 +50,7 @@ var (
 		Name:         "skill",
 		Title:        "加载专项技能说明",
 		Description:  "用于加载当前命中的专项技能说明文档。仅在本轮已命中 Skill 时可用，适合将专项处理规则按需注入上下文。",
-		SourceType:   "builtin",
+		SourceType:   enums.ToolSourceTypeBuiltin,
 		AutoInjected: true,
 	}
 	GraphTriageServiceRequest = ToolSpec{
@@ -55,7 +59,7 @@ var (
 		Name:          "triage_service_request",
 		Title:         "升级分流判断",
 		Description:   "Graph Tool。用于综合分析当前对话，判断应继续解答、整理工单草稿还是转人工，并在需要建单时一并整理工单草稿。",
-		SourceType:    "graph",
+		SourceType:    enums.ToolSourceTypeGraph,
 		RuntimeStatic: true,
 		Appendix: strings.TrimSpace(`
 当你需要判断“继续解答 / 建单 / 转人工”这类复杂升级路径时，优先先调用 triage_service_request 这个 Graph Tool，并遵守以下规则：
@@ -72,7 +76,7 @@ var (
 		Name:          "analyze_conversation",
 		Title:         "分析对话风险与摘要",
 		Description:   "Graph Tool。用于整理当前对话摘要、识别风险信号，并给出继续解答、建单或转人工的建议。",
-		SourceType:    "graph",
+		SourceType:    enums.ToolSourceTypeGraph,
 		RuntimeStatic: true,
 		Appendix: strings.TrimSpace(`
 当对话可能涉及投诉升级、退款赔偿、明显负面情绪、是否要建单、是否要转人工等复杂判断时，优先调用 analyze_conversation 这个 Graph Tool，并遵守以下规则：
@@ -88,7 +92,7 @@ var (
 		Name:          "prepare_ticket_draft",
 		Title:         "整理工单草稿",
 		Description:   "Graph Tool。用于根据当前会话和已收集信息整理工单草稿，输出建议标题、描述、缺失字段和追问建议。",
-		SourceType:    "graph",
+		SourceType:    enums.ToolSourceTypeGraph,
 		RuntimeStatic: true,
 		Appendix: strings.TrimSpace(`
 当用户已经表达了建单、投诉、报障、售后处理等诉求，但工单标题、描述或问题整理还比较散乱时，优先调用 prepare_ticket_draft 这个 Graph Tool，并遵守以下规则：
@@ -104,7 +108,7 @@ var (
 		Name:          "create_ticket_with_confirmation",
 		Title:         "创建工单确认流程",
 		Description:   "Graph Tool。用于封装建单参数整理、用户确认、真正建单和结果返回的确定性流程。",
-		SourceType:    "graph",
+		SourceType:    enums.ToolSourceTypeGraph,
 		DirectAccess:  true,
 		RuntimeStatic: true,
 		Aliases:       []string{"builtin/create_ticket_with_confirmation"},
@@ -123,7 +127,7 @@ var (
 		Name:          "handoff_to_human",
 		Title:         "转人工确认流程",
 		Description:   "Graph Tool。用于封装转人工原因整理、用户确认、真正转人工和结果返回的确定性流程。",
-		SourceType:    "graph",
+		SourceType:    enums.ToolSourceTypeGraph,
 		DirectAccess:  true,
 		RuntimeStatic: true,
 		Appendix: strings.TrimSpace(`
@@ -229,18 +233,18 @@ func GetRegisteredToolIdentity(toolCode string) (serverCode, toolName string, ok
 	return spec.ServerCode, spec.Name, true
 }
 
-func ResolveToolSourceType(toolCode string) string {
+func ResolveToolSourceType(toolCode string) enums.ToolSourceType {
 	if spec, ok := GetRegisteredToolSpec(toolCode); ok {
 		return spec.SourceType
 	}
 	toolCode = strings.TrimSpace(toolCode)
 	switch {
 	case strings.HasPrefix(toolCode, "graph/"):
-		return "graph"
+		return enums.ToolSourceTypeGraph
 	case strings.HasPrefix(toolCode, "builtin/"):
-		return "builtin"
+		return enums.ToolSourceTypeBuiltin
 	default:
-		return "mcp"
+		return enums.ToolSourceTypeMCP
 	}
 }
 
@@ -309,7 +313,7 @@ func BuildToolAppendicesForCodes(hasDynamicMCPTools bool, toolCodes []string) []
 	return ret
 }
 
-func BuildToolMetadata(toolCode string) (serverCode, toolName, sourceType string, ok bool) {
+func BuildToolMetadata(toolCode string) (serverCode, toolName string, sourceType enums.ToolSourceType, ok bool) {
 	spec, ok := GetRegisteredToolSpec(toolCode)
 	if !ok {
 		return "", "", ResolveToolSourceType(toolCode), false
@@ -331,7 +335,7 @@ func ResolveToolMetadata(toolCode string, fallbackName string) ToolMetadata {
 		ToolCode:   toolCode,
 		ServerCode: strings.TrimSpace(serverCode),
 		ToolName:   strings.TrimSpace(toolName),
-		SourceType: strings.TrimSpace(sourceType),
+		SourceType: sourceType,
 	}
 }
 
diff --git a/internal/services/tool_catalog_service.go b/internal/services/tool_catalog_service.go
index fb3cca3..22a6860 100644
--- a/internal/services/tool_catalog_service.go
+++ b/internal/services/tool_catalog_service.go
@@ -7,6 +7,7 @@ import (
 
 	"cs-agent/internal/ai/mcps"
 	"cs-agent/internal/pkg/config"
+	"cs-agent/internal/pkg/enums"
 	"cs-agent/internal/pkg/errorsx"
 	"cs-agent/internal/pkg/toolx"
 )
@@ -23,7 +24,7 @@ type MCPToolCatalogItem struct {
 	ToolCode     string
 	ServerCode   string
 	ToolName     string
-	SourceType   string
+	SourceType   enums.ToolSourceType
 	AutoInjected bool
 	Title        string
 	Description  string
@@ -69,7 +70,7 @@ func (s *toolCatalogService) ListMCPTools(ctx context.Context) ([]MCPToolCatalog
 				ToolCode:     toolx.BuildMCPToolCode(serverCode, item.Name),
 				ServerCode:   serverCode,
 				ToolName:     strings.TrimSpace(item.Name),
-				SourceType:   "mcp",
+				SourceType:   enums.ToolSourceTypeMCP,
 				AutoInjected: false,
 				Title:        strings.TrimSpace(item.Title),
 				Description:  strings.TrimSpace(item.Description),
diff --git a/web/app/(console)/ai-agents/_components/edit.tsx b/web/app/(console)/ai-agents/_components/edit.tsx
index 338aa13..4c411b6 100644
--- a/web/app/(console)/ai-agents/_components/edit.tsx
+++ b/web/app/(console)/ai-agents/_components/edit.tsx
@@ -38,6 +38,7 @@ import {
   type CreateAIAgentPayload,
   type KnowledgeBase,
   type MCPToolCatalogItem,
+  type MCPToolSourceType,
   type SkillDefinition,
   fetchAIAgent,
   fetchAIConfigsAll,
@@ -63,7 +64,7 @@ type DirectToolOption = {
   value: string;
   label: string;
   meta: DirectToolItem;
-  sourceType: string;
+  sourceType: MCPToolSourceType;
   autoInjected: boolean;
   groupLabel: string;
 };
diff --git a/web/lib/api/admin.ts b/web/lib/api/admin.ts
index c31313e..3597af0 100644
--- a/web/lib/api/admin.ts
+++ b/web/lib/api/admin.ts
@@ -359,11 +359,13 @@ export type MCPToolInfo = {
   outputSchema?: unknown
 }
 
+export type MCPToolSourceType = "mcp" | "graph" | "builtin"
+
 export type MCPToolCatalogItem = {
   toolCode: string
   serverCode: string
   toolName: string
-  sourceType: string
+  sourceType: MCPToolSourceType
   autoInjected: boolean
   title: string
   description: string