added missing documentation

Capnp.Net.Runtime/DynamicSerializerState.cs

@@ -89,6 +89,11 @@ namespace Capnp
         /// <exception cref="InvalidOperationException">The object type was already set to something different</exception>
         public new void SetStruct(ushort dataCount, ushort ptrCount) => base.SetStruct(dataCount, ptrCount);
 
+        /// <summary>
+        /// Determines the underyling object to be a capability.
+        /// </summary>
+        /// <param name="capabilityIndex">Capability table index, or null to encode a null pointer</param>
+        /// <exception cref="InvalidOperationException">The object type was already set to something different</exception>
         public new void SetCapability(uint? capabilityIndex) => base.SetCapability(capabilityIndex);
 
         /// <summary>

Capnp.Net.Runtime/Rpc/Impatient.cs

@@ -156,6 +156,16 @@ namespace Capnp.Rpc
             }
         }
 
+        /// <summary>
+        /// Unwraps given capability. Unwrapping walks the chain of promised capabilities and awaits their resolutions,
+        /// until we get the finally resolved capability. If it is the capability, the method returns a null reference.
+        /// If the capability is broken (resolved to exception, dependent answer faulted or cancelled, RPC endpoint closed),
+        /// it throws an exception.
+        /// </summary>
+        /// <typeparam name="TInterface">Capability interface</typeparam>
+        /// <param name="cap">capability to unwrap</param>
+        /// <returns>Task returning the eventually resolved capability</returns>
+        /// <exception cref="RpcException">Capability is broken</exception>
         public static async Task<TInterface?> Unwrap<TInterface>(this TInterface cap) where TInterface: class, IDisposable
         {
             using var proxy = cap as Proxy;

Capnp.Net.Runtime/SerializerState.cs

@@ -497,6 +497,11 @@ namespace Capnp
             }
         }
 
+        /// <summary>
+        /// Determines the underyling object to be a capability.
+        /// </summary>
+        /// <param name="capabilityIndex">Capability table index, or null to encode a null pointer</param>
+        /// <exception cref="InvalidOperationException">The object type was already set to something different</exception>
         protected void SetCapability(uint? capabilityIndex)
         {
             if (capabilityIndex.HasValue)