Updates AI Assistant reqs for Security, Obs/Search, Agent Builder (#3967)

Fixes #3693 by updating our requirements sections for all three
Assistant pages. This effort started out an emphasis on updating the
information about which Kibana privileges are required, but I decided to
revisit the whole requirements section.

So far I've only made changes to the AI Assistant for Obs and Search and
the AI Assistant for Security pages because I don't know enough about
Agent Builder requirements and I couldn't find any obviously applicable
privs in the UI.

Author: benironside

solutions/observability/observability-ai-assistant.md

@@ -32,26 +32,20 @@ The {{obs-ai-assistant}} helps you:
 
 ## Requirements [obs-ai-requirements]
 
-The AI assistant requires the following:
+To set up or use AI assistant, you need the following:
 
-- An **Elastic deployment**:
+* An appropriate [Elastic subscription](https://www.elastic.co/subscriptions)
 
-  - For **{{observability}}**: {{stack}} version **8.9** or later, or an **{{observability}} serverless project**.
+* The `Observability AI Assistant: All` {{kib}} privilege
 
-  - For **Search**: {{stack}}  version **8.16.0** or later, or **{{serverless-short}} {{es}} project**.
+* An [LLM connector](/solutions/security/ai/set-up-connectors-for-large-language-models-llm.md)
 
-    - To run {{obs-ai-assistant}} on a self-hosted Elastic stack, you need an [appropriate license](https://www.elastic.co/subscriptions).
-
-- An account with a third-party generative AI provider that preferably supports function calling. If your AI provider does not support function calling, you can configure [AI Assistant settings](../../solutions/observability/observability-ai-assistant.md#obs-ai-settings) to simulate function calling, but this might affect performance.
-
-  - The free tier offered by third-party generative AI provider may not be sufficient for the proper functioning of the AI assistant. In most cases, a paid subscription to one of the supported providers is required.
-
-    Refer to the [documentation](kibana://reference/connectors-kibana/gen-ai-connectors.md) for your provider to learn about supported and default models.
-
-* The knowledge base requires a 4 GB {{ml}} node.
-  - In {{ecloud}} or {{ece}}, if you have Machine Learning autoscaling enabled, Machine Learning nodes will be started when using the knowledge base and AI Assistant. Therefore using these features will incur additional costs.
-
-* A self-deployed connector service if you're using [content connectors](elasticsearch://reference/search-connectors/index.md) to populate external data into the knowledge base.
+* (Optional) To use [knowledge base](#obs-ai-add-data): 
+  - A 4 GB {{ml}} node
+    :::{note}
+    In {{ecloud}} or {{ece}}, if you have {{ml}} autoscaling enabled, {{ml}} nodes automatically start when using the knowledge base and AI Assistant. Therefore using these features incurs additional costs.
+    :::
+  - If you want to use [content connectors](elasticsearch://reference/search-connectors/index.md) to add external data to knowledge base: A self-deployed connector service
 
 ## Manage access to AI Assistant
 

solutions/security/ai/ai-assistant.md

@@ -29,9 +29,9 @@ The Elastic AI Assistant is designed to enhance your analysis with smart dialogu
 ::::{admonition} Requirements
 * {applies_to}`stack: ga` An [Enterprise subscription](https://www.elastic.co/pricing).
 * {applies_to}`serverless: ga` An {{sec-serverless}} project with the [EASE or Security Analytics Complete feature tier](/deploy-manage/deploy/elastic-cloud/project-settings.md).
-* To use AI Assistant, the **Elastic AI Assistant : All** and **Actions and Connectors : Read** [privileges](/deploy-manage/users-roles/cluster-or-deployment-auth/kibana-privileges.md).
+* To use AI Assistant, the **Elastic AI Assistant: All** Security [privilege](/deploy-manage/users-roles/cluster-or-deployment-auth/kibana-privileges.md) and the **Actions and Connectors: Read** management [privilege](/deploy-manage/users-roles/cluster-or-deployment-auth/kibana-privileges.md).
 * To set up AI Assistant, the **Actions and Connectors : All** [privilege](/deploy-manage/users-roles/cluster-or-deployment-auth/kibana-privileges.md).
-* A [generative AI connector](/solutions/security/ai/set-up-connectors-for-large-language-models-llm.md), which AI Assistant uses to generate responses.
+* An [LLM connector](/solutions/security/ai/set-up-connectors-for-large-language-models-llm.md), which AI Assistant uses to generate responses.
 * A [machine learning node](/explore-analyze/machine-learning/setting-up-machine-learning.md).
 ::::