diff --git a/README.md b/README.md
index 693859b8..ba8390a3 100644
--- a/README.md
+++ b/README.md
@@ -39,6 +39,7 @@ According to the documentation from [Google Gemini](https://drive.google.com/fil
 - Role
 - Context
 - Goal
+- Tone
 - Constraints
 - Instructions
 - Examples
diff --git a/generator/src/main/resources/pml.xsd b/generator/src/main/resources/pml.xsd
index 5e16dd75..3d93d9b0 100644
--- a/generator/src/main/resources/pml.xsd
+++ b/generator/src/main/resources/pml.xsd
@@ -8,6 +8,7 @@
             <xs:sequence>
                 <xs:element ref="metadata" minOccurs="0"/>
                 <xs:element ref="role"/>
+                <xs:element ref="tone" minOccurs="0"/>
                 <xs:element ref="context" minOccurs="0"/>
                 <xs:element ref="goal"/>
                 <xs:element ref="constraints" minOccurs="0"/>
@@ -68,6 +69,9 @@
     <!-- System role -->
     <xs:element name="role" type="xs:string"/>
 
+    <!-- Tone specification -->
+    <xs:element name="tone" type="xs:string"/>
+
     <!-- Goal statement -->
     <xs:element name="goal">
         <xs:complexType mixed="true">