Build evaluation report in CI and when enabled

Directory.Build.props

@@ -102,12 +102,6 @@
     <UseVSTestRunner>true</UseVSTestRunner>
   </PropertyGroup>
 
-  <PropertyGroup>
-    <!-- By default turn off the NodeJS tools required to build the reports for Microsoft.Extensions.AI.Evaluation.Reporting 
-         This should be enabled in CI and also for report development work. -->
-    <EnableEvaluationReportBuild>false</EnableEvaluationReportBuild>
-  </PropertyGroup>
-
   <!-- Common properties -->
   <Import Project="$(MSBuildThisFileDirectory)\eng\MSBuild\Analyzers.props" />
   <Import Project="$(MSBuildThisFileDirectory)\eng\MSBuild\Packaging.props" />

src/Libraries/Microsoft.Extensions.AI.Evaluation.Reporting/CSharp/Microsoft.Extensions.AI.Evaluation.Reporting.csproj

@@ -1,5 +1,12 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
+  <!-- 
+    NOTE: To build and test the TypeScript code that this project depends on, set the 'EnableEvaluationReportBuild'
+    environment variable to 'true'. Note that the TypeScript build depends on Node.js tools. So you will need to
+    install the latest version of Node.js from https://nodejs.org/ as a prerequisite before setting the
+    'EnableEvaluationReportBuild' environment variable.
+  -->
+
   <PropertyGroup>
     <Description>A library for aggregating and reporting evaluation data. This library also includes support for caching LLM responses.</Description>
     <TargetFrameworks>$(TargetFrameworks);netstandard2.0</TargetFrameworks>