diff --git a/api/lib/opentelemetry/trace/event.rb b/api/lib/opentelemetry/trace/event.rb
index bc2bacab3..d7b50dd29 100644
--- a/api/lib/opentelemetry/trace/event.rb
+++ b/api/lib/opentelemetry/trace/event.rb
@@ -19,7 +19,7 @@ class Event
 
       # Returns the frozen attributes for this event
       #
-      # @return [Hash<String, Object>]
+      # @return [Hash{String => String, Numeric, Boolean}]
       attr_reader :attributes
 
       # Returns the timestamp for this event
@@ -30,8 +30,9 @@ class Event
       # Returns a new immutable {Event}.
       #
       # @param [String] name The name of this event
-      # @param [optional Hash<String, Object>] attributes A hash of attributes for this
-      #   event. Attributes will be frozen during Event initialization.
+      # @param [optional Hash{String => String, Numeric, Boolean}]
+      #   attributes A hash of attributes for this event. Attributes will be
+      #   frozen during Event initialization.
       # @param [optional Time] timestamp The timestamp for this event.
       #   Defaults to Time.now.
       # @return [Event]
diff --git a/api/lib/opentelemetry/trace/link.rb b/api/lib/opentelemetry/trace/link.rb
index f6121956e..143d2003a 100644
--- a/api/lib/opentelemetry/trace/link.rb
+++ b/api/lib/opentelemetry/trace/link.rb
@@ -22,14 +22,15 @@ class Link
 
       # Returns the frozen attributes for this link.
       #
-      # @return [Hash<String, Object>]
+      # @return [Hash{String => String, Numeric, Boolean}]
       attr_reader :attributes
 
       # Returns a new immutable {Link}.
       #
       # @param [SpanContext] span_context The context of the linked {Span}.
-      # @param [optional Hash<String, Object>] attributes A hash of attributes for
-      #   this link. Attributes will be frozen during Link initialization.
+      # @param [optional Hash{String => String, Numeric, Boolean}] attributes A
+      #   hash of attributes for this link. Attributes will be frozen during
+      #   Link initialization.
       # @return [Link]
       def initialize(span_context, attributes = nil)
         @context = span_context
diff --git a/api/lib/opentelemetry/trace/span.rb b/api/lib/opentelemetry/trace/span.rb
index d5ef59915..716290d3d 100644
--- a/api/lib/opentelemetry/trace/span.rb
+++ b/api/lib/opentelemetry/trace/span.rb
@@ -77,10 +77,10 @@ def set_attribute(key, value)
       #
       # @param [optional String] name Optional name of the event. This is
       #   required if a block is not given.
-      # @param [optional Hash<String, Object>] attributes One or more key:value
-      #   pairs, where the keys must be strings and the values may be string,
-      #   boolean or numeric type. This argument should only be used when
-      #   passing in a name.
+      # @param [optional Hash{String => String, Numeric, Boolean}] attributes
+      #   One or more key:value pairs, where the keys must be strings and the
+      #   values may be string, boolean or numeric type. This argument should
+      #   only be used when passing in a name.
       # @param [optional Time] timestamp Optional timestamp for the event.
       #   This argument should only be used when passing in a name.
       #
diff --git a/sdk/lib/opentelemetry/sdk/trace/samplers/result.rb b/sdk/lib/opentelemetry/sdk/trace/samplers/result.rb
index 349048b22..bc52105a3 100644
--- a/sdk/lib/opentelemetry/sdk/trace/samplers/result.rb
+++ b/sdk/lib/opentelemetry/sdk/trace/samplers/result.rb
@@ -19,7 +19,7 @@ class Result
 
           # Returns a frozen hash of attributes to be attached span.
           #
-          # @return [Hash<String, Object>]
+          # @return [Hash{String => String, Numeric, Boolean}]
           attr_reader :attributes
 
           # Returns a new sampling result with the specified decision and
@@ -27,8 +27,9 @@ class Result
           #
           # @param [Symbol] decision Whether or not a span should be sampled
           #   and/or record events.
-          # @param [optional Hash<String, Object>] attributes A frozen or freezable hash
-          #   containing attributes to be attached to the span.
+          # @param [optional Hash{String => String, Numeric, Boolean}]
+          #   attributes A frozen or freezable hash containing attributes to be
+          #   attached to the span.
           def initialize(decision:, attributes: nil)
             @decision = decision
             @attributes = attributes.freeze || EMPTY_HASH
diff --git a/sdk/lib/opentelemetry/sdk/trace/span.rb b/sdk/lib/opentelemetry/sdk/trace/span.rb
index 12dc3b8ff..b87f387dc 100644
--- a/sdk/lib/opentelemetry/sdk/trace/span.rb
+++ b/sdk/lib/opentelemetry/sdk/trace/span.rb
@@ -24,7 +24,7 @@ class Span < OpenTelemetry::Trace::Span
         # use of SpanProcesses and should not be considered part of the public
         # interface for instrumentation.
         #
-        # @return [Hash<String, Object>] may be nil.
+        # @return [Hash{String => String, Numeric, Boolean}] may be nil.
         def attributes
           # Don't bother synchronizing. Access by SpanProcessors is expected to
           # be serialized.
@@ -96,10 +96,10 @@ def set_attribute(key, value)
         #
         # @param [optional String] name Optional name of the event. This is
         #   required if a block is not given.
-        # @param [optional Hash<String, Object>] attributes One or more key:value
-        #   pairs, where the keys must be strings and the values may be string,
-        #   boolean or numeric type. This argument should only be used when
-        #   passing in a name.
+        # @param [optional Hash{String => String, Numeric, Boolean}] attributes
+        #   One or more key:value pairs, where the keys must be strings and the
+        #   values may be string, boolean or numeric type. This argument should
+        #   only be used when passing in a name.
         # @param [optional Time] timestamp Optional timestamp for the event.
         #   This argument should only be used when passing in a name.
         #