diff --git a/src/mcp/server.ts b/src/mcp/server.ts
index 6f10614..a9f1828 100644
--- a/src/mcp/server.ts
+++ b/src/mcp/server.ts
@@ -781,7 +781,7 @@ Please verify the tool name and ensure the tool is properly registered.`;
             mcp_client_name: params?.clientInfo?.name || '',
             mcp_client_version: params?.clientInfo?.version || '',
             mcp_protocol_version: params?.protocolVersion || '',
-            mcp_client_capabilities: capabilities ? JSON.stringify(capabilities) : '',
+            mcp_client_capabilities: capabilities || null,
             mcp_session_id: mcpSessionId || '',
             transport_type: this.options.transportType || '',
             tool_name: toolFullName,
diff --git a/src/types.ts b/src/types.ts
index d660d46..77bfef5 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -303,7 +303,7 @@ export interface ToolCallTelemetryProperties {
     mcp_client_name: string;
     mcp_client_version: string;
     mcp_protocol_version: string;
-    mcp_client_capabilities: string;
+    mcp_client_capabilities: Record<string, unknown> | null;
     mcp_session_id: string;
     transport_type: string;
     tool_name: string;
diff --git a/tests/unit/telemetry.test.ts b/tests/unit/telemetry.test.ts
index 5a10535..260c86b 100644
--- a/tests/unit/telemetry.test.ts
+++ b/tests/unit/telemetry.test.ts
@@ -23,7 +23,7 @@ describe('telemetry', () => {
             mcp_client_name: 'test-client',
             mcp_client_version: '1.0.0',
             mcp_protocol_version: '2024-11-05',
-            mcp_client_capabilities: '{}',
+            mcp_client_capabilities: {},
             mcp_session_id: 'session-123',
             transport_type: 'stdio',
             tool_name: 'test-tool',
@@ -42,7 +42,7 @@ describe('telemetry', () => {
                 mcp_client_name: 'test-client',
                 mcp_client_version: '1.0.0',
                 mcp_protocol_version: '2024-11-05',
-                mcp_client_capabilities: '{}',
+                mcp_client_capabilities: {},
                 mcp_session_id: 'session-123',
                 transport_type: 'stdio',
                 tool_name: 'test-tool',
@@ -59,7 +59,7 @@ describe('telemetry', () => {
             mcp_client_name: 'test-client',
             mcp_client_version: '1.0.0',
             mcp_protocol_version: '2024-11-05',
-            mcp_client_capabilities: '{}',
+            mcp_client_capabilities: {},
             mcp_session_id: 'session-123',
             transport_type: 'stdio',
             tool_name: 'test-tool',