diff --git a/x-pack/test_serverless/api_integration/test_suites/observability/ai_assistant/tests/complete/functions/summarize.spec.ts b/x-pack/test_serverless/api_integration/test_suites/observability/ai_assistant/tests/complete/functions/summarize.spec.ts
index f949268aa730..823dd15f46b6 100644
--- a/x-pack/test_serverless/api_integration/test_suites/observability/ai_assistant/tests/complete/functions/summarize.spec.ts
+++ b/x-pack/test_serverless/api_integration/test_suites/observability/ai_assistant/tests/complete/functions/summarize.spec.ts
@@ -11,6 +11,13 @@ import {
   LlmProxy,
   createLlmProxy,
 } from '@kbn/test-suites-xpack/observability_ai_assistant_api_integration/common/create_llm_proxy';
+import {
+  clearKnowledgeBase,
+  createKnowledgeBaseModel,
+  deleteInferenceEndpoint,
+  deleteKnowledgeBaseModel,
+  TINY_ELSER,
+} from '@kbn/test-suites-xpack/observability_ai_assistant_api_integration/tests/knowledge_base/helpers';
 import { FtrProviderContext } from '../../../common/ftr_provider_context';
 import { invokeChatCompleteWithFunctionRequest } from './helpers';
 import {
@@ -22,12 +29,15 @@ import type { InternalRequestHeader, RoleCredentials } from '../../../../../../.
 export default function ApiTest({ getService }: FtrProviderContext) {
   const supertest = getService('supertest');
   const log = getService('log');
+  const ml = getService('ml');
+  const es = getService('es');
   const observabilityAIAssistantAPIClient = getService('observabilityAIAssistantAPIClient');
   const svlUserManager = getService('svlUserManager');
   const svlCommonApi = getService('svlCommonApi');
 
-  // Skipped until Elser is available in tests
-  describe.skip('when calling summarize function', () => {
+  describe('when calling summarize function', function () {
+    // TODO: https://github.com/elastic/kibana/issues/192751
+    this.tags(['skipMKI']);
     let roleAuthc: RoleCredentials;
     let internalReqHeader: InternalRequestHeader;
     let proxy: LlmProxy;
@@ -36,6 +46,19 @@ export default function ApiTest({ getService }: FtrProviderContext) {
     before(async () => {
       roleAuthc = await svlUserManager.createM2mApiKeyWithRoleScope('editor');
       internalReqHeader = svlCommonApi.getInternalRequestHeader();
+
+      await createKnowledgeBaseModel(ml);
+      await observabilityAIAssistantAPIClient
+        .slsAdmin({
+          endpoint: 'POST /internal/observability_ai_assistant/kb/setup',
+          params: {
+            query: {
+              model_id: TINY_ELSER.id,
+            },
+          },
+        })
+        .expect(200);
+
       proxy = await createLlmProxy(log);
       connectorId = await createProxyActionConnector({
         supertest,
@@ -57,10 +80,10 @@ export default function ApiTest({ getService }: FtrProviderContext) {
           name: 'summarize',
           trigger: MessageRole.User,
           arguments: JSON.stringify({
-            id: 'my-id',
+            title: 'My Title',
             text: 'Hello world',
             is_correction: false,
-            confidence: 1,
+            confidence: 'high',
             public: false,
           }),
         },
@@ -72,6 +95,9 @@ export default function ApiTest({ getService }: FtrProviderContext) {
     after(async () => {
       proxy.close();
       await deleteActionConnector({ supertest, connectorId, log, roleAuthc, internalReqHeader });
+      await deleteKnowledgeBaseModel(ml);
+      await clearKnowledgeBase(es);
+      await deleteInferenceEndpoint({ es });
     });
 
     it('persists entry in knowledge base', async () => {
@@ -80,12 +106,20 @@ export default function ApiTest({ getService }: FtrProviderContext) {
         params: {
           query: {
             query: '',
-            sortBy: 'doc_id',
+            sortBy: 'title',
             sortDirection: 'asc',
           },
         },
       });
 
+      const { role, public: isPublic, text, type, user, title } = res.body.entries[0];
+
+      expect(role).to.eql('assistant_summarization');
+      expect(isPublic).to.eql(false);
+      expect(text).to.eql('Hello world');
+      expect(type).to.eql('contextual');
+      expect(user?.name).to.eql('elastic_editor'); // "editor" in stateful
+      expect(title).to.eql('My Title');
       expect(res.body.entries).to.have.length(1);
     });
   });