Minor updates

hearth/lib/hearth/telemetry.rb

@@ -28,7 +28,7 @@ module Hearth
   #     client = Service::Client.new(telemetry_provider: otel_provider)
   #
   # If a provider isn't supported, you can implement your own support by
-  # following the no-op interfaces within `Hearth::Telemetry`.
+  # following the telemetry interfaces defined in RBS.
   module Telemetry
     # @return true if opentelemetry-sdk is available
     def self.otel_loaded?

hearth/lib/hearth/telemetry/otel.rb

@@ -18,18 +18,35 @@ def initialize
 
     # OpenTelemetry-based ContextManager
     class OTelContextManager < ContextManager
+      # Returns current context
+      #
+      # @return [Context]
       def current
         OpenTelemetry::Context.current
       end
 
+      # Returns the current span from current context
+      #
+      # @return Span
       def current_span
         OpenTelemetry::Trace.current_span
       end
 
+      # Associates a Context with the caller’s current execution unit.
+      # Returns a token to be used with the matching call to detach.
+      #
+      # @param [Context] context The new context
+      # @return [Object] token A token to be used when detaching
       def attach(context)
         OpenTelemetry::Context.attach(context)
       end
 
+      # Restore the previous Context associated with the current
+      # execution unit to the value it had before attaching a
+      # specified Context.
+      #
+      # @param [Object] token The token provided by matching the call to attach
+      # @return [Boolean] True if the calls matched, False otherwise
       def detach(token)
         OpenTelemetry::Context.detach(token)
       end

hearth/sig/lib/hearth/telemetry.rbs

@@ -12,6 +12,10 @@ module Hearth
       def initialize: () -> void
     end
 
+    class OTelContextManager
+      include _ContextManager
+    end
+
     interface _TracerProvider
       def tracer: (?String name) -> _Tracer
     end