Update articles/ai-foundry/concepts/observability.md

Co-authored-by: changliu2 <[email protected]>

Author: lgayhardt

articles/ai-foundry/concepts/observability.md

@@ -61,7 +61,7 @@ To learn more, see [Textual similarity evaluators](./evaluation-evaluators/textu
 |--|--|--|
 | Retrieval | Measures how effectively the system retrieves relevant information. | Query , context |
 | Document Retrieval | Measures accuracy in retrieval results given ground truth. | Ground truth , retrieved documents,  |
-| Groundedness | Measures how consistent the response is with respect to the retrieved context. | Query, context, response |
+| Groundedness | Measures how consistent the response is with respect to the retrieved context. | (optional) Query, context, response |
 | Groundedness Pro | Measures whether the response is consistent with respect to the retrieved context. | Query, context, response |
 | Relevance | Measures how relevant the response is with respect to the query. | Query, response|
 | Response Completeness | Measures to what extent the response is complete (not missing critical information) with respect to the ground truth. | Response, ground truth |