Update capability-hosts.md

Author: howieleung

articles/ai-foundry/agents/concepts/capability-hosts.md

@@ -89,6 +89,8 @@ PUT https://management.azure.com/subscriptions/{subscriptionId}/resourceGroups/{
 ```
 
 **Project capability host**
+
+This configuration overrides service defaults and any account-level settings. All agents in this project will use your specified resources:
 ```http
 PUT https://management.azure.com/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.CognitiveServices/accounts/{accountName}/projects/{projectName}/capabilityHosts/{name}?api-version=2025-06-01