diff --git a/agent-client-protocol-schema/src/v1/elicitation.rs b/agent-client-protocol-schema/src/v1/elicitation.rs
index e64d8b087..c169940d7 100644
--- a/agent-client-protocol-schema/src/v1/elicitation.rs
+++ b/agent-client-protocol-schema/src/v1/elicitation.rs
@@ -64,7 +64,7 @@ pub enum ElicitationSchemaType {
     Object,
 }
 
-/// A titled enum option with a const value and human-readable title.
+/// A titled enum option with a const value, human-readable title, and optional description.
 #[serde_as]
 #[skip_serializing_none]
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
@@ -75,6 +75,11 @@ pub struct EnumOption {
     pub value: String,
     /// Human-readable title for this option.
     pub title: String,
+    /// Human-readable description.
+    #[serde_as(deserialize_as = "DefaultOnError")]
+    #[schemars(extend("x-deserialize-default-on-error" = true))]
+    #[serde(default)]
+    pub description: Option<String>,
     /// The _meta property is reserved by ACP to allow clients and agents to attach additional
     /// metadata to their interactions. Implementations MUST NOT make assumptions about values at
     /// these keys.
@@ -94,10 +99,18 @@ impl EnumOption {
         Self {
             value: value.into(),
             title: title.into(),
+            description: None,
             meta: None,
         }
     }
 
+    /// Human-readable description.
+    #[must_use]
+    pub fn description(mut self, description: impl IntoOption<String>) -> Self {
+        self.description = description.into_option();
+        self
+    }
+
     /// The _meta property is reserved by ACP to allow clients and agents to attach additional
     /// metadata to their interactions. Implementations MUST NOT make assumptions about values at
     /// these keys.
@@ -2615,7 +2628,7 @@ mod tests {
         let schema = ElicitationSchema::new().property(
             "country",
             StringPropertySchema::new().one_of(vec![
-                EnumOption::new("us", "United States"),
+                EnumOption::new("us", "United States").description("Use US English spelling."),
                 EnumOption::new("uk", "United Kingdom"),
             ]),
             true,
@@ -2627,12 +2640,20 @@ mod tests {
         assert_eq!(one_of.len(), 2);
         assert_eq!(one_of[0]["const"], "us");
         assert_eq!(one_of[0]["title"], "United States");
+        assert_eq!(one_of[0]["description"], "Use US English spelling.");
+        assert!(one_of[1].get("description").is_none());
 
         let roundtripped: ElicitationSchema = serde_json::from_value(json).unwrap();
         if let ElicitationPropertySchema::String(s) =
             roundtripped.properties.get("country").unwrap()
         {
-            assert_eq!(s.one_of.as_ref().unwrap().len(), 2);
+            let one_of = s.one_of.as_ref().unwrap();
+            assert_eq!(one_of.len(), 2);
+            assert_eq!(
+                one_of[0].description.as_deref(),
+                Some("Use US English spelling.")
+            );
+            assert!(one_of[1].description.is_none());
         } else {
             panic!("expected String variant");
         }
diff --git a/agent-client-protocol-schema/src/v2/conversion.rs b/agent-client-protocol-schema/src/v2/conversion.rs
index bdef9c7ff..43a899d59 100644
--- a/agent-client-protocol-schema/src/v2/conversion.rs
+++ b/agent-client-protocol-schema/src/v2/conversion.rs
@@ -7616,10 +7616,16 @@ impl IntoV1 for super::EnumOption {
     type Output = crate::v1::EnumOption;
 
     fn into_v1(self) -> Result<Self::Output> {
-        let Self { value, title, meta } = self;
+        let Self {
+            value,
+            title,
+            description,
+            meta,
+        } = self;
         Ok(crate::v1::EnumOption {
             value: value.into_v1()?,
             title: title.into_v1()?,
+            description: description.into_v1()?,
             meta: meta.into_v1()?,
         })
     }
@@ -7630,10 +7636,16 @@ impl IntoV2 for crate::v1::EnumOption {
     type Output = super::EnumOption;
 
     fn into_v2(self) -> Result<Self::Output> {
-        let Self { value, title, meta } = self;
+        let Self {
+            value,
+            title,
+            description,
+            meta,
+        } = self;
         Ok(super::EnumOption {
             value: value.into_v2()?,
             title: title.into_v2()?,
+            description: description.into_v2()?,
             meta: meta.into_v2()?,
         })
     }
diff --git a/agent-client-protocol-schema/src/v2/elicitation.rs b/agent-client-protocol-schema/src/v2/elicitation.rs
index 71941e761..1feb8541f 100644
--- a/agent-client-protocol-schema/src/v2/elicitation.rs
+++ b/agent-client-protocol-schema/src/v2/elicitation.rs
@@ -69,7 +69,7 @@ pub enum ElicitationSchemaType {
     Object,
 }
 
-/// A titled enum option with a const value and human-readable title.
+/// A titled enum option with a const value, human-readable title, and optional description.
 #[serde_as]
 #[skip_serializing_none]
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
@@ -80,6 +80,11 @@ pub struct EnumOption {
     pub value: String,
     /// Human-readable title for this option.
     pub title: String,
+    /// Human-readable description.
+    #[serde_as(deserialize_as = "DefaultOnError")]
+    #[schemars(extend("x-deserialize-default-on-error" = true))]
+    #[serde(default)]
+    pub description: Option<String>,
     /// The _meta property is reserved by ACP to allow clients and agents to attach additional
     /// metadata to their interactions. Implementations MUST NOT make assumptions about values at
     /// these keys.
@@ -99,10 +104,18 @@ impl EnumOption {
         Self {
             value: value.into(),
             title: title.into(),
+            description: None,
             meta: None,
         }
     }
 
+    /// Human-readable description.
+    #[must_use]
+    pub fn description(mut self, description: impl IntoOption<String>) -> Self {
+        self.description = description.into_option();
+        self
+    }
+
     /// The _meta property is reserved by ACP to allow clients and agents to attach additional
     /// metadata to their interactions. Implementations MUST NOT make assumptions about values at
     /// these keys.
@@ -2560,7 +2573,7 @@ mod tests {
         let schema = ElicitationSchema::new().property(
             "country",
             StringPropertySchema::new().one_of(vec![
-                EnumOption::new("us", "United States"),
+                EnumOption::new("us", "United States").description("Use US English spelling."),
                 EnumOption::new("uk", "United Kingdom"),
             ]),
             true,
@@ -2572,12 +2585,20 @@ mod tests {
         assert_eq!(one_of.len(), 2);
         assert_eq!(one_of[0]["const"], "us");
         assert_eq!(one_of[0]["title"], "United States");
+        assert_eq!(one_of[0]["description"], "Use US English spelling.");
+        assert!(one_of[1].get("description").is_none());
 
         let roundtripped: ElicitationSchema = serde_json::from_value(json).unwrap();
         if let ElicitationPropertySchema::String(s) =
             roundtripped.properties.get("country").unwrap()
         {
-            assert_eq!(s.one_of.as_ref().unwrap().len(), 2);
+            let one_of = s.one_of.as_ref().unwrap();
+            assert_eq!(one_of.len(), 2);
+            assert_eq!(
+                one_of[0].description.as_deref(),
+                Some("Use US English spelling.")
+            );
+            assert!(one_of[1].description.is_none());
         } else {
             panic!("expected String variant");
         }
diff --git a/docs/protocol/v1/draft/schema.mdx b/docs/protocol/v1/draft/schema.mdx
index 94c4ace97..3d174486a 100644
--- a/docs/protocol/v1/draft/schema.mdx
+++ b/docs/protocol/v1/draft/schema.mdx
@@ -4423,7 +4423,7 @@ See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/v1/d
 
 ## <span class="font-mono">EnumOption</span>
 
-A titled enum option with a const value and human-readable title.
+A titled enum option with a const value, human-readable title, and optional description.
 
 **Type:** Object
 
@@ -4440,6 +4440,9 @@ See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/v1/d
 <ResponseField name="const" type={"string"} required>
   The constant value for this option.
 </ResponseField>
+<ResponseField name="description" type={"string | null"} >
+  Human-readable description.
+</ResponseField>
 <ResponseField name="title" type={"string"} required>
   Human-readable title for this option.
 </ResponseField>
diff --git a/docs/protocol/v2/draft/schema.mdx b/docs/protocol/v2/draft/schema.mdx
index 0b36faea7..f4e53095d 100644
--- a/docs/protocol/v2/draft/schema.mdx
+++ b/docs/protocol/v2/draft/schema.mdx
@@ -4178,7 +4178,7 @@ See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/v2/d
 
 ## <span class="font-mono">EnumOption</span>
 
-A titled enum option with a const value and human-readable title.
+A titled enum option with a const value, human-readable title, and optional description.
 
 **Type:** Object
 
@@ -4195,6 +4195,9 @@ See protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/v2/d
 <ResponseField name="const" type={"string"} required>
   The constant value for this option.
 </ResponseField>
+<ResponseField name="description" type={"string | null"} >
+  Human-readable description.
+</ResponseField>
 <ResponseField name="title" type={"string"} required>
   Human-readable title for this option.
 </ResponseField>
diff --git a/docs/rfds/elicitation.mdx b/docs/rfds/elicitation.mdx
index 8733f2ec3..b96734722 100644
--- a/docs/rfds/elicitation.mdx
+++ b/docs/rfds/elicitation.mdx
@@ -99,12 +99,18 @@ Agents send elicitation requests when they need information from the user. This
         "oneOf": [
           {
             "const": "conservative",
-            "title": "Conservative - Minimal changes"
+            "title": "Conservative - Minimal changes",
+            "description": "Make minimal changes and avoid broad cleanup."
+          },
+          {
+            "const": "balanced",
+            "title": "Balanced (Recommended)",
+            "description": "Fix the issue and clean nearby code when it lowers risk."
           },
-          { "const": "balanced", "title": "Balanced (Recommended)" },
           {
             "const": "aggressive",
-            "title": "Aggressive - Maximum optimization"
+            "title": "Aggressive - Maximum optimization",
+            "description": "Refactor more broadly to optimize the affected area."
           }
         ],
         "default": "balanced"
@@ -270,9 +276,21 @@ Single-select enum (with titles):
   "title": "Color Selection",
   "description": "Choose your favorite color",
   "oneOf": [
-    { "const": "#FF0000", "title": "Red" },
-    { "const": "#00FF00", "title": "Green" },
-    { "const": "#0000FF", "title": "Blue" }
+    {
+      "const": "#FF0000",
+      "title": "Red",
+      "description": "High emphasis and warning-oriented."
+    },
+    {
+      "const": "#00FF00",
+      "title": "Green",
+      "description": "Positive status and success-oriented."
+    },
+    {
+      "const": "#0000FF",
+      "title": "Blue",
+      "description": "Neutral and informational."
+    }
   ],
   "default": "#FF0000"
 }
@@ -306,9 +324,21 @@ Multi-select enum (with titles):
   "maxItems": 2,
   "items": {
     "anyOf": [
-      { "const": "#FF0000", "title": "Red" },
-      { "const": "#00FF00", "title": "Green" },
-      { "const": "#0000FF", "title": "Blue" }
+      {
+        "const": "#FF0000",
+        "title": "Red",
+        "description": "High emphasis and warning-oriented."
+      },
+      {
+        "const": "#00FF00",
+        "title": "Green",
+        "description": "Positive status and success-oriented."
+      },
+      {
+        "const": "#0000FF",
+        "title": "Blue",
+        "description": "Neutral and informational."
+      }
     ]
   },
   "default": ["#FF0000", "#00FF00"]
@@ -373,9 +403,21 @@ The agent sends an `elicitation/create` request when it needs information from t
           "type": "string",
           "title": "Refactoring Strategy",
           "oneOf": [
-            { "const": "conservative", "title": "Conservative" },
-            { "const": "balanced", "title": "Balanced (Recommended)" },
-            { "const": "aggressive", "title": "Aggressive" }
+            {
+              "const": "conservative",
+              "title": "Conservative",
+              "description": "Make minimal changes and avoid broad cleanup."
+            },
+            {
+              "const": "balanced",
+              "title": "Balanced (Recommended)",
+              "description": "Fix the issue and clean nearby code when it lowers risk."
+            },
+            {
+              "const": "aggressive",
+              "title": "Aggressive",
+              "description": "Refactor more broadly to optimize the affected area."
+            }
           ],
           "default": "balanced"
         }
diff --git a/schema/v1/schema.unstable.json b/schema/v1/schema.unstable.json
index 3f15cb948..d0d3b6964 100644
--- a/schema/v1/schema.unstable.json
+++ b/schema/v1/schema.unstable.json
@@ -1770,7 +1770,7 @@
       ]
     },
     "EnumOption": {
-      "description": "A titled enum option with a const value and human-readable title.",
+      "description": "A titled enum option with a const value, human-readable title, and optional description.",
       "type": "object",
       "properties": {
         "const": {
@@ -1781,6 +1781,11 @@
           "description": "Human-readable title for this option.",
           "type": "string"
         },
+        "description": {
+          "description": "Human-readable description.",
+          "type": ["string", "null"],
+          "x-deserialize-default-on-error": true
+        },
         "_meta": {
           "description": "The _meta property is reserved by ACP to allow clients and agents to attach additional\nmetadata to their interactions. Implementations MUST NOT make assumptions about values at\nthese keys.\n\nSee protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/extensibility)",
           "type": ["object", "null"],
diff --git a/schema/v2/schema.unstable.json b/schema/v2/schema.unstable.json
index 8a31ef090..dca3447b7 100644
--- a/schema/v2/schema.unstable.json
+++ b/schema/v2/schema.unstable.json
@@ -2396,7 +2396,7 @@
       ]
     },
     "EnumOption": {
-      "description": "A titled enum option with a const value and human-readable title.",
+      "description": "A titled enum option with a const value, human-readable title, and optional description.",
       "type": "object",
       "properties": {
         "const": {
@@ -2407,6 +2407,11 @@
           "description": "Human-readable title for this option.",
           "type": "string"
         },
+        "description": {
+          "description": "Human-readable description.",
+          "type": ["string", "null"],
+          "x-deserialize-default-on-error": true
+        },
         "_meta": {
           "description": "The _meta property is reserved by ACP to allow clients and agents to attach additional\nmetadata to their interactions. Implementations MUST NOT make assumptions about values at\nthese keys.\n\nSee protocol docs: [Extensibility](https://agentclientprotocol.com/protocol/v2/draft/extensibility)",
           "type": ["object", "null"],