Update comments

Author: BenjaminMichaelis

src/System.CommandLine.Subsystems/Subsystems/Annotations/AnnotationAccessor.cs

@@ -8,14 +8,40 @@ namespace System.CommandLine.Subsystems.Annotations;
 /// <summary>
 /// Allows associating an annotation with a <see cref="CliSymbol"/>. The annotation will be stored by the accessor's owner <see cref="CliSubsystem"/>.
 /// </summary>
+/// <remarks>
+/// The annotation will be stored by the accessor's owner <see cref="CliSubsystem"/>. 
+/// </summary>
+/// <typeparam name="TValue">The type of value to be stored</typeparam>
+/// <param name="owner">The subsystem that this annotation store data for.</param>
+/// <param name="id">The identifier for this annotation, since subsystems may have multiple annotations.</param>
+/// <param name="defaultValue">The default value to return if the annotation is not set.</param>
 public struct AnnotationAccessor<TValue>(CliSubsystem owner, AnnotationId<TValue> id, TValue? defaultValue = default)
 {
     /// <summary>
-    /// The ID of the annotation
+    /// The identifier for this annotation, since subsystems may have multiple annotations.
     /// </summary>
     public AnnotationId<TValue> Id { get; } = id;
+
+    /// <summary>
+    /// Store a value for the annotation and symbol
+    /// </summary>
+    /// <param name="symbol">The CliSymbol the value is for.</param>
+    /// <param name="value">The value to store.</param>
     public readonly void Set(CliSymbol symbol, TValue value) => owner.SetAnnotation(symbol, Id, value);
+
+    /// <summary>
+    /// Retrieve the value for the annotation and symbol
+    /// </summary>
+    /// <param name="symbol">The CliSymbol the value is for.</param>
+    /// <param name="value">The value to retrieve/</param>
+    /// <returns>True if the value was found, false otherwise.</returns>
     public readonly bool TryGet(CliSymbol symbol, [NotNullWhen(true)] out TValue? value) => owner.TryGetAnnotation(symbol, Id, out value);
+
+    /// <summary>
+    /// Retrieve the value for the annotation and symbol
+    /// </summary>
+    /// <param name="symbol">The CliSymbol the value is for.</param>
+    /// <returns>The retrieved value or <see cref="defaultValue"/> if the value was not found.</returns>
     public readonly TValue? Get(CliSymbol symbol)
     {
         if (TryGet(symbol, out var value))