[Obs AI Assistant] Fix contextual insights scoring (elastic#214259)

Closes elastic#209572

### Summary

Scoring in contextual insights is broken because the
`get_contextual_insight_instructions` tool call is not followed by the
tool response. This happens because we replace the last user message (in
this case tool response) with the user message related to scoring.

### Solution

We should include the tool call name when replacing this message, so
that it gets converted to inference messages correctly here:

https://github.com/elastic/kibana/blob/07012811b29b487a3b4a664469c7a198355e44bf/x-pack/platform/plugins/shared/observability_ai_assistant/common/convert_messages_for_inference.ts#L60-L81


### Checklist

- [x] The PR description includes the appropriate Release Notes section,
and the correct `release_note:*` label is applied per the
[guidelines](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)

Author: viduni94

x-pack/platform/plugins/shared/observability_ai_assistant/common/convert_messages_for_inference.ts

@@ -66,6 +66,7 @@ export function convertMessagesForInference(
           msg.role === InferenceMessageRole.Assistant &&
           msg.toolCalls?.[0]?.function.name === message.message.name
       ) as AssistantMessage | undefined;
+
       if (!toolCallRequest) {
         throw new Error(`Could not find tool call request for ${message.message.name}`);
       }

x-pack/platform/plugins/shared/observability_ai_assistant/server/functions/context.ts

@@ -63,12 +63,14 @@ export function registerContextFunction({
         );
 
         const userPrompt = userMessage?.message.content!;
+        const userMessageFunctionName = userMessage?.message.name;
 
         const { scores, relevantDocuments, suggestions } = await recallAndScore({
           recall: client.recall,
           chat,
           logger: resources.logger,
           userPrompt,
+          userMessageFunctionName,
           context: screenDescription,
           messages,
           signal,

x-pack/platform/plugins/shared/observability_ai_assistant/server/utils/recall/recall_and_score.test.ts

@@ -0,0 +1,265 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import { RecalledSuggestion, recallAndScore } from './recall_and_score';
+import { scoreSuggestions } from './score_suggestions';
+import { MessageRole, type Message } from '../../../common';
+import type { FunctionCallChatFunction } from '../../service/types';
+import { AnalyticsServiceStart } from '@kbn/core/server';
+import { Logger } from '@kbn/logging';
+import { recallRankingEventType } from '../../analytics/recall_ranking';
+
+jest.mock('./score_suggestions', () => ({
+  scoreSuggestions: jest.fn(),
+}));
+
+export const sampleMessages: Message[] = [
+  {
+    '@timestamp': '2025-03-13T14:53:11.240Z',
+    message: { role: MessageRole.User, content: 'test' },
+  },
+];
+
+export const normalConversationMessages: Message[] = [
+  {
+    '@timestamp': '2025-03-12T21:00:13.980Z',
+    message: { role: MessageRole.User, content: 'What is my favourite color?' },
+  },
+  {
+    '@timestamp': '2025-03-12T21:00:14.920Z',
+    message: {
+      function_call: { name: 'context', trigger: MessageRole.Assistant },
+      role: MessageRole.Assistant,
+      content: '',
+    },
+  },
+];
+
+export const contextualInsightsMessages: Message[] = [
+  {
+    '@timestamp': '2025-03-12T21:01:21.111Z',
+    message: {
+      role: MessageRole.User,
+      content: "I'm looking at an alert and trying to understand why it was triggered",
+    },
+  },
+  {
+    '@timestamp': '2025-03-12T21:01:21.111Z',
+    message: {
+      role: MessageRole.Assistant,
+      function_call: {
+        name: 'get_contextual_insight_instructions',
+        trigger: MessageRole.Assistant,
+        arguments: '{}',
+      },
+    },
+  },
+  {
+    '@timestamp': '2025-03-12T21:01:21.111Z',
+    message: {
+      role: MessageRole.User,
+      content:
+        '{"instructions":"I\'m an SRE. I am looking at an alert that was triggered. I want to understand why it was triggered......}',
+      name: 'get_contextual_insight_instructions',
+    },
+  },
+  {
+    '@timestamp': '2025-03-12T21:01:21.984Z',
+    message: {
+      function_call: { name: 'context', trigger: MessageRole.Assistant },
+      role: MessageRole.Assistant,
+      content: '',
+    },
+  },
+];
+
+describe('recallAndScore', () => {
+  const mockRecall = jest.fn();
+  const mockChat = jest.fn() as unknown as FunctionCallChatFunction;
+  const mockLogger = { error: jest.fn(), debug: jest.fn() } as unknown as Logger;
+  const mockAnalytics = { reportEvent: jest.fn() } as unknown as AnalyticsServiceStart;
+  const signal = new AbortController().signal;
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  describe('when no documents are recalled', () => {
+    let result: {
+      relevantDocuments?: RecalledSuggestion[];
+      scores?: Array<{ id: string; score: number }>;
+      suggestions: RecalledSuggestion[];
+    };
+
+    beforeEach(async () => {
+      mockRecall.mockResolvedValue([]);
+
+      result = await recallAndScore({
+        recall: mockRecall,
+        chat: mockChat,
+        analytics: mockAnalytics,
+        userPrompt: 'What is my favorite color?',
+        context: 'Some context',
+        messages: sampleMessages,
+        logger: mockLogger,
+        signal,
+      });
+    });
+
+    it('returns empty suggestions', async () => {
+      expect(result).toEqual({ relevantDocuments: [], scores: [], suggestions: [] });
+    });
+
+    it('invokes recall with user prompt and screen context', async () => {
+      expect(mockRecall).toHaveBeenCalledWith({
+        queries: [
+          { text: 'What is my favorite color?', boost: 3 },
+          { text: 'Some context', boost: 1 },
+        ],
+      });
+    });
+
+    it('does not score the suggestions', async () => {
+      expect(scoreSuggestions).not.toHaveBeenCalled();
+    });
+  });
+
+  it('handles errors when scoring fails', async () => {
+    mockRecall.mockResolvedValue([{ id: 'doc1', text: 'Hello world', score: 0.5 }]);
+    (scoreSuggestions as jest.Mock).mockRejectedValue(new Error('Scoring failed'));
+
+    const result = await recallAndScore({
+      recall: mockRecall,
+      chat: mockChat,
+      analytics: mockAnalytics,
+      userPrompt: 'test',
+      context: 'context',
+      messages: sampleMessages,
+      logger: mockLogger,
+      signal,
+    });
+
+    expect(mockLogger.error).toHaveBeenCalledWith(
+      expect.stringContaining('Error scoring documents: Scoring failed'),
+      expect.any(Object)
+    );
+    expect(result.suggestions.length).toBe(1);
+    expect(result.suggestions[0].id).toBe('doc1');
+  });
+
+  it('calls scoreSuggestions with correct arguments', async () => {
+    const recalledDocs = [{ id: 'doc1', text: 'Hello world', score: 0.8 }];
+    mockRecall.mockResolvedValue(recalledDocs);
+    (scoreSuggestions as jest.Mock).mockResolvedValue({
+      scores: [{ id: 'doc1', score: 7 }],
+      relevantDocuments: recalledDocs,
+    });
+
+    await recallAndScore({
+      recall: mockRecall,
+      chat: mockChat,
+      analytics: mockAnalytics,
+      userPrompt: 'test',
+      context: 'context',
+      messages: sampleMessages,
+      logger: mockLogger,
+      signal,
+    });
+
+    expect(scoreSuggestions).toHaveBeenCalledWith({
+      suggestions: recalledDocs,
+      logger: mockLogger,
+      messages: sampleMessages,
+      userPrompt: 'test',
+      userMessageFunctionName: undefined,
+      context: 'context',
+      signal,
+      chat: mockChat,
+    });
+  });
+
+  it('handles the normal conversation flow correctly', async () => {
+    mockRecall.mockResolvedValue([
+      { id: 'fav_color', text: 'My favourite color is blue.', score: 0.9 },
+    ]);
+    (scoreSuggestions as jest.Mock).mockResolvedValue({
+      scores: [{ id: 'fav_color', score: 7 }],
+      relevantDocuments: [{ id: 'fav_color', text: 'My favourite color is blue.' }],
+    });
+
+    const result = await recallAndScore({
+      recall: mockRecall,
+      chat: mockChat,
+      analytics: mockAnalytics,
+      userPrompt: "What's my favourite color?",
+      context: '',
+      messages: normalConversationMessages,
+      logger: mockLogger,
+      signal,
+    });
+
+    expect(result.relevantDocuments).toEqual([
+      { id: 'fav_color', text: 'My favourite color is blue.' },
+    ]);
+    expect(mockRecall).toHaveBeenCalled();
+    expect(scoreSuggestions).toHaveBeenCalled();
+  });
+
+  it('handles contextual insights conversation flow correctly', async () => {
+    mockRecall.mockResolvedValue([
+      { id: 'alert_cause', text: 'The alert was triggered due to high CPU usage.', score: 0.85 },
+    ]);
+    (scoreSuggestions as jest.Mock).mockResolvedValue({
+      scores: [{ id: 'alert_cause', score: 6 }],
+      relevantDocuments: [
+        { id: 'alert_cause', text: 'The alert was triggered due to high CPU usage.' },
+      ],
+    });
+
+    const result = await recallAndScore({
+      recall: mockRecall,
+      chat: mockChat,
+      analytics: mockAnalytics,
+      userPrompt: "I'm looking at an alert and trying to understand why it was triggered",
+      context: 'User is analyzing an alert',
+      messages: contextualInsightsMessages,
+      logger: mockLogger,
+      signal,
+    });
+
+    expect(result.relevantDocuments).toEqual([
+      { id: 'alert_cause', text: 'The alert was triggered due to high CPU usage.' },
+    ]);
+    expect(mockRecall).toHaveBeenCalled();
+    expect(scoreSuggestions).toHaveBeenCalled();
+  });
+
+  it('reports analytics with the correct structure', async () => {
+    const recalledDocs = [{ id: 'doc1', text: 'Hello world', score: 0.8 }];
+    mockRecall.mockResolvedValue(recalledDocs);
+    (scoreSuggestions as jest.Mock).mockResolvedValue({
+      scores: [{ id: 'doc1', score: 7 }],
+      relevantDocuments: recalledDocs,
+    });
+
+    await recallAndScore({
+      recall: mockRecall,
+      chat: mockChat,
+      analytics: mockAnalytics,
+      userPrompt: 'test',
+      context: 'context',
+      messages: sampleMessages,
+      logger: mockLogger,
+      signal,
+    });
+
+    expect(mockAnalytics.reportEvent).toHaveBeenCalledWith(
+      recallRankingEventType,
+      expect.objectContaining({ scoredDocuments: [{ elserScore: 0.8, llmScore: 7 }] })
+    );
+  });
+});

x-pack/platform/plugins/shared/observability_ai_assistant/server/utils/recall/recall_and_score.ts

@@ -21,6 +21,7 @@ export async function recallAndScore({
   chat,
   analytics,
   userPrompt,
+  userMessageFunctionName,
   context,
   messages,
   logger,
@@ -30,6 +31,7 @@ export async function recallAndScore({
   chat: FunctionCallChatFunction;
   analytics: AnalyticsServiceStart;
   userPrompt: string;
+  userMessageFunctionName?: string;
   context: string;
   messages: Message[];
   logger: Logger;
@@ -62,6 +64,7 @@ export async function recallAndScore({
       logger,
       messages,
       userPrompt,
+      userMessageFunctionName,
       context,
       signal,
       chat,