Internal Release 0.5.0

Bump protocol version to 2025-03-26
Provide fallback value for tool_name
Make configuration per server
Add support for tool annotations
document tool annotations

lib/model_context_protocol/tool.rb

@@ -15,18 +15,47 @@ module ModelContextProtocol
       end
     end
 
+    class Annotations
+      attr_reader :title, :read_only_hint, :destructive_hint, :idempotent_hint, :open_world_hint
+
+      def initialize(title: nil, read_only_hint: nil, destructive_hint: nil, idempotent_hint: nil, open_world_hint: nil)
+        @title = title
+        @read_only_hint = read_only_hint
+        @destructive_hint = destructive_hint
+        @idempotent_hint = idempotent_hint
+        @open_world_hint = open_world_hint
+      end
+
+      def to_h
+        {
+          title:,
+          readOnlyHint: read_only_hint,
+          destructiveHint: destructive_hint,
+          idempotentHint: idempotent_hint,
+          openWorldHint: open_world_hint,
+        }.compact
+      end
+    end
+
     class << self
       NOT_SET = Object.new
 
       attr_reader :description_value
       attr_reader :input_schema_value
+      attr_reader :annotations_value
 
       def call(*args, context:)
         raise NotImplementedError, "Subclasses must implement call"
       end
 
       def to_h
-        { name: name_value, description: description_value, inputSchema: input_schema_value }
+        result = {
+          name: name_value,
+          description: description_value,
+          inputSchema: input_schema_value,
+        }
+        result[:annotations] = annotations_value.to_h if annotations_value
+        result
       end
 
       def inherited(subclass)
@@ -34,11 +63,12 @@ module ModelContextProtocol
         subclass.instance_variable_set(:@name_value, nil)
         subclass.instance_variable_set(:@description_value, nil)
         subclass.instance_variable_set(:@input_schema_value, nil)
+        subclass.instance_variable_set(:@annotations_value, nil)
       end
 
       def tool_name(value = NOT_SET)
         if value == NOT_SET
-          @name_value
+          name_value
         else
           @name_value = value
         end
@@ -64,11 +94,20 @@ module ModelContextProtocol
         end
       end
 
-      def define(name: nil, description: nil, input_schema: nil, &block)
+      def annotations(hash = NOT_SET)
+        if hash == NOT_SET
+          @annotations_value
+        else
+          @annotations_value = Annotations.new(**hash)
+        end
+      end
+
+      def define(name: nil, description: nil, input_schema: nil, annotations: nil, &block)
         Class.new(self) do
           tool_name name
           description description
           input_schema input_schema
+          self.annotations(annotations) if annotations
           define_singleton_method(:call) do |*args, context:|
             instance_exec(*args, context:, &block)
           end