Add a retriever

Add a retriever to your prompt to augment and add context to your prompts with AI search results.

Avant de commencer

Role required: sn_skill_builder.admin

Pourquoi et quand exécuter cette tâche

Using a retriever in a skill enhances the relevance and coherence of a response by pulling relevant information from a source and then feeding it to a large language model (LLM) to create the final output. This process leads to smoother conversational flow and better scalability as data grows, without requiring model fine-tuning.

A retriever enables the chatbot to access external knowledge by fetching relevant background information, resulting in more factual, in-depth, and informed responses.

Procédure

1. Navigate to All > Now Assist Skill Kit > Home.
2. Create a new skill or select the skill that you want to add a retriever to.
3. Select the Tool editor tab.
4. Select (+) icon to add a node.
5. Select Tool node.
6. Select Retriever from the drop-down menu.
7. Select Configure retriever.
8. On the form, fill in the fields.

   Tableau 1. Add tool form

   Field	Description
   Name	The name for the retriever.
   Search query	The information that you want to search for. It can be static text or a skill input.
   Search space type	Table-based Search-profile-based
   Search profile	A group of search sources.
   Search sources	Tables in ServiceNow that have been indexed and can be used for search.
   Fields returned	The fields that you want returned from the search sources and sent to the large language model (LLM).
   Limit	The maximum number of results that are returned.
   Search criteria	Hybrid Semantic Keyword Remarque : If you choose Hybrid or Semantic, you can make selections for chunking and reranking. To learn more about chunking and reranking, see Retriever chunking and reranking.

9. Select Next.
10. If you selected Hybrid or Semantic search criteria, select a semantic index.
    A semantic index enables you to search for data based on contextual meaning.
11. Facultatif : If you selected Hybrid or Semantic search criteria, select Advanced to change the document matching threshold.
    The document matching threshold is the threshold for semantic matching. The default value is 0. You can input any value from 0 to 1. You can get more precise results with a higher value.
12. Select Next.
    Remarque :

    If you selected Hybrid or Semantic search criteria, see Retriever chunking and reranking to complete setting up your retriever.
13. Review the retriever tool information.
14. Select Add tool.

• Retriever chunking and reranking
  When you’re building a skill prompt that uses a retriever you can use chunking and reranking to enhance the accuracy and relevance of your responses.