Clarify update analyzer base analyzer guidance

Author: anhtnt90dev

sdk/contentunderstanding/azure-ai-contentunderstanding/samples/README.md

@@ -119,7 +119,11 @@ Lists all available analyzers in your Microsoft Foundry resource. Shows how to d
 ### Sample 08: Update Analyzer
 
 #### `sample_update_analyzer.py` / `sample_update_analyzer_async.py`
-Updates an existing custom analyzer's description and tags. Only `description` and `tags` can be updated with `update_analyzer`; use `begin_create_analyzer` with `allow_replace=True` to change create-only properties such as `models`, `field_schema`, `config`, `base_analyzer_id`, `dynamic_field_schema`, `processing_location`, or `knowledge_sources`.
+Updates an existing custom analyzer's description and tags. Only `description` and `tags` can be updated
+with `update_analyzer`. Use `begin_create_analyzer` with `allow_replace=True` to change create-only
+properties such as `models`, `field_schema`, `config`, `dynamic_field_schema`, `processing_location`, or
+`knowledge_sources`. If `base_analyzer_id` is included in an update request, it must match the existing
+analyzer.
 
 **Key concepts:**
 - Updating analyzer description

sdk/contentunderstanding/azure-ai-contentunderstanding/samples/async_samples/sample_update_analyzer_async.py

@@ -15,9 +15,10 @@
     - Description: Update the analyzer's description
     - Tags: Add or update tags
 
-    To change create-only properties such as models, field_schema, config, base_analyzer_id,
+    To change create-only properties such as models, field_schema, config,
     dynamic_field_schema, processing_location, or knowledge_sources, use begin_create_analyzer
-    with allow_replace=True.
+    with allow_replace=True. If base_analyzer_id is included in an update request, it must
+    match the existing analyzer.
 
 USAGE:
     python sample_update_analyzer_async.py
@@ -98,7 +99,8 @@ async def main() -> None:
             print(f"  Tags: {tags_str}")
 
         # Create an updated analyzer with the properties supported by update_analyzer.
-        # Other analyzer properties are create-only and require begin_create_analyzer(..., allow_replace=True).
+        # Keep base_analyzer_id unchanged; other create-only properties require
+        # begin_create_analyzer(..., allow_replace=True).
         updated_analyzer = ContentAnalyzer(
             base_analyzer_id=current_analyzer.base_analyzer_id,
             description="Updated description",

sdk/contentunderstanding/azure-ai-contentunderstanding/samples/sample_update_analyzer.py

@@ -15,9 +15,10 @@
     - Description: Update the analyzer's description
     - Tags: Add or update tags
 
-    To change create-only properties such as models, field_schema, config, base_analyzer_id,
+    To change create-only properties such as models, field_schema, config,
     dynamic_field_schema, processing_location, or knowledge_sources, use begin_create_analyzer
-    with allow_replace=True.
+    with allow_replace=True. If base_analyzer_id is included in an update request, it must
+    match the existing analyzer.
 
 USAGE:
     python sample_update_analyzer.py
@@ -96,7 +97,8 @@ def main() -> None:
         print(f"  Tags: {tags_str}")
 
     # Create an updated analyzer with the properties supported by update_analyzer.
-    # Other analyzer properties are create-only and require begin_create_analyzer(..., allow_replace=True).
+    # Keep base_analyzer_id unchanged; other create-only properties require
+    # begin_create_analyzer(..., allow_replace=True).
     updated_analyzer = ContentAnalyzer(
         base_analyzer_id=current_analyzer.base_analyzer_id,
         description="Updated description",