diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index b3960c050..62fc21a00 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-    ".": "1.12.0"
+    ".": "1.12.1"
 }
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5e3fc0aa0..aa515df65 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Changelog
 
+## [1.12.1](https://github.com/google/adk-java/compare/v1.12.0...v1.12.1) (2026-10-15)
+
+
+### Bug Fixes
+
+* **mcp:** emit valid JSON Schema when converting ADK tools to MCP tools ([60250a9](https://github.com/google/adk-java/commit/60250a930ec50b9e63a4bef8b6d3949fa0b31817))
+
 ## [1.12.0](https://github.com/google/adk-java/compare/v1.11.0...v1.12.0) (2026-10-14)
 
 
diff --git a/README.md b/README.md
index 7b55a6e09..4b17ea937 100644
--- a/README.md
+++ b/README.md
@@ -50,13 +50,13 @@ If you're using Maven, add the following to your dependencies:
 <dependency>
   <groupId>com.google.adk</groupId>
   <artifactId>google-adk</artifactId>
-  <version>1.12.0</version>
+  <version>1.12.1</version>
 </dependency>
 <!-- Dev UI -->
 <dependency>
     <groupId>com.google.adk</groupId>
     <artifactId>google-adk-dev</artifactId>
-    <version>1.12.0</version>
+    <version>1.12.1</version>
 </dependency>
 ```
 
diff --git a/a2a/pom.xml b/a2a/pom.xml
index 59e57214b..9abb6e8cc 100644
--- a/a2a/pom.xml
+++ b/a2a/pom.xml
@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.google.adk</groupId>
     <artifactId>google-adk-parent</artifactId>
-    <version>1.12.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
+    <version>1.12.1</version><!-- {x-version-update:google-adk:current} -->
   </parent>
 
   <artifactId>google-adk-a2a</artifactId>
diff --git a/contrib/firestore-session-service/pom.xml b/contrib/firestore-session-service/pom.xml
index 3b3c2cb15..d2cd9a17e 100644
--- a/contrib/firestore-session-service/pom.xml
+++ b/contrib/firestore-session-service/pom.xml
@@ -20,7 +20,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-parent</artifactId>
-        <version>1.12.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.12.1</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>../../pom.xml</relativePath>
     </parent>
 
diff --git a/contrib/langchain4j/pom.xml b/contrib/langchain4j/pom.xml
index f3b07c8f6..adaabe965 100644
--- a/contrib/langchain4j/pom.xml
+++ b/contrib/langchain4j/pom.xml
@@ -20,7 +20,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-parent</artifactId>
-        <version>1.12.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.12.1</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>../../pom.xml</relativePath>
     </parent>
 
diff --git a/contrib/planners/pom.xml b/contrib/planners/pom.xml
index a0ea28027..badb7be46 100644
--- a/contrib/planners/pom.xml
+++ b/contrib/planners/pom.xml
@@ -20,7 +20,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-parent</artifactId>
-        <version>1.12.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.12.1</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>../../pom.xml</relativePath>
     </parent>
 
diff --git a/contrib/spring-ai/pom.xml b/contrib/spring-ai/pom.xml
index 398fb2d63..9d314854a 100644
--- a/contrib/spring-ai/pom.xml
+++ b/contrib/spring-ai/pom.xml
@@ -20,7 +20,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-parent</artifactId>
-        <version>1.12.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.12.1</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>../../pom.xml</relativePath>
     </parent>
 
diff --git a/core/pom.xml b/core/pom.xml
index 89363f1fa..a2d2221d6 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>com.google.adk</groupId>
     <artifactId>google-adk-parent</artifactId>
-    <version>1.12.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
+    <version>1.12.1</version><!-- {x-version-update:google-adk:current} -->
   </parent>
 
   <artifactId>google-adk</artifactId>
diff --git a/core/src/main/java/com/google/adk/Version.java b/core/src/main/java/com/google/adk/Version.java
index da5f4ab04..e94605346 100644
--- a/core/src/main/java/com/google/adk/Version.java
+++ b/core/src/main/java/com/google/adk/Version.java
@@ -22,7 +22,7 @@
  */
 public final class Version {
   // Don't touch this, release-please should keep it up to date.
-  public static final String JAVA_ADK_VERSION = "1.12.0"; // x-release-please-released-version
+  public static final String JAVA_ADK_VERSION = "1.12.1"; // x-release-please-released-version
 
   private Version() {}
 }
diff --git a/dev/pom.xml b/dev/pom.xml
index 682399ea7..b06ba6c1c 100644
--- a/dev/pom.xml
+++ b/dev/pom.xml
@@ -18,7 +18,7 @@
   <parent>
     <groupId>com.google.adk</groupId>
     <artifactId>google-adk-parent</artifactId>
-    <version>1.12.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
+    <version>1.12.1</version><!-- {x-version-update:google-adk:current} -->
   </parent>
 
   <artifactId>google-adk-dev</artifactId>
diff --git a/examples/a2a_basic/pom.xml b/examples/a2a_basic/pom.xml
index 734e051a1..e4324b1a2 100644
--- a/examples/a2a_basic/pom.xml
+++ b/examples/a2a_basic/pom.xml
@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.google.adk</groupId>
     <artifactId>google-adk-examples</artifactId>
-    <version>1.12.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
+    <version>1.12.1</version><!-- {x-version-update:google-adk:current} -->
     <relativePath>..</relativePath>
   </parent>
 
diff --git a/examples/a2a_server/pom.xml b/examples/a2a_server/pom.xml
index eb9e3b1b0..a902246b1 100644
--- a/examples/a2a_server/pom.xml
+++ b/examples/a2a_server/pom.xml
@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.google.adk</groupId>
     <artifactId>google-adk-examples</artifactId>
-    <version>1.12.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
+    <version>1.12.1</version><!-- {x-version-update:google-adk:current} -->
     <relativePath>..</relativePath>
   </parent>
 
diff --git a/examples/configagent/pom.xml b/examples/configagent/pom.xml
index 0d19ace77..a51ddd35f 100644
--- a/examples/configagent/pom.xml
+++ b/examples/configagent/pom.xml
@@ -5,7 +5,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-examples</artifactId>
-        <version>1.12.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.12.1</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>..</relativePath>
     </parent>
 
diff --git a/examples/contextcaching/pom.xml b/examples/contextcaching/pom.xml
index 87254f444..e9d4954e7 100644
--- a/examples/contextcaching/pom.xml
+++ b/examples/contextcaching/pom.xml
@@ -20,7 +20,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-examples</artifactId>
-        <version>1.12.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.12.1</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>..</relativePath>
     </parent>
 
diff --git a/examples/helloworld/pom.xml b/examples/helloworld/pom.xml
index 755ef7bc6..648696310 100644
--- a/examples/helloworld/pom.xml
+++ b/examples/helloworld/pom.xml
@@ -20,7 +20,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-examples</artifactId>
-        <version>1.12.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.12.1</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>..</relativePath>
     </parent>
 
diff --git a/examples/mcpfilesystem/pom.xml b/examples/mcpfilesystem/pom.xml
index 38899c59d..9b48384e9 100644
--- a/examples/mcpfilesystem/pom.xml
+++ b/examples/mcpfilesystem/pom.xml
@@ -20,7 +20,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-examples</artifactId>
-        <version>1.12.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.12.1</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>..</relativePath>
     </parent>
 
diff --git a/examples/pom.xml b/examples/pom.xml
index 0b334b9a4..285e68882 100644
--- a/examples/pom.xml
+++ b/examples/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>com.google.adk</groupId>
     <artifactId>google-adk-parent</artifactId>
-    <version>1.12.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
+    <version>1.12.1</version><!-- {x-version-update:google-adk:current} -->
     <relativePath>..</relativePath>
   </parent>
 
diff --git a/maven_plugin/examples/custom_tools/pom.xml b/maven_plugin/examples/custom_tools/pom.xml
index 40d7fbfe7..89d642dc5 100644
--- a/maven_plugin/examples/custom_tools/pom.xml
+++ b/maven_plugin/examples/custom_tools/pom.xml
@@ -4,7 +4,7 @@
 
     <groupId>com.example</groupId>
     <artifactId>custom-tools-example</artifactId>
-    <version>1.12.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
+    <version>1.12.1</version><!-- {x-version-update:google-adk:current} -->
     <packaging>jar</packaging>
 
     <name>ADK Custom Tools Example</name>
diff --git a/maven_plugin/examples/simple-agent/pom.xml b/maven_plugin/examples/simple-agent/pom.xml
index 26f88e06a..4cae82c69 100644
--- a/maven_plugin/examples/simple-agent/pom.xml
+++ b/maven_plugin/examples/simple-agent/pom.xml
@@ -4,7 +4,7 @@
 
     <groupId>com.example</groupId>
     <artifactId>simple-adk-agent</artifactId>
-    <version>1.12.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
+    <version>1.12.1</version><!-- {x-version-update:google-adk:current} -->
     <packaging>jar</packaging>
 
     <name>Simple ADK Agent Example</name>
diff --git a/maven_plugin/pom.xml b/maven_plugin/pom.xml
index 5aeabe575..738007dca 100644
--- a/maven_plugin/pom.xml
+++ b/maven_plugin/pom.xml
@@ -5,7 +5,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-parent</artifactId>
-        <version>1.12.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.12.1</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>../pom.xml</relativePath>
     </parent>
 
diff --git a/pom.xml b/pom.xml
index 016200d16..a196dc664 100644
--- a/pom.xml
+++ b/pom.xml
@@ -17,7 +17,7 @@
 
   <groupId>com.google.adk</groupId>
   <artifactId>google-adk-parent</artifactId>
-  <version>1.12.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
+  <version>1.12.1</version><!-- {x-version-update:google-adk:current} -->
   <packaging>pom</packaging>
 
   <name>Google Agent Development Kit Maven Parent POM</name>
diff --git a/tokt/pom.xml b/tokt/pom.xml
index 6945a4852..87ca281ec 100644
--- a/tokt/pom.xml
+++ b/tokt/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>com.google.adk</groupId>
     <artifactId>google-adk-parent</artifactId>
-    <version>1.12.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
+    <version>1.12.1</version><!-- {x-version-update:google-adk:current} -->
   </parent>
 
   <artifactId>google-adk-tokt</artifactId>
diff --git a/tutorials/city-time-weather/pom.xml b/tutorials/city-time-weather/pom.xml
index e62854787..816915552 100644
--- a/tutorials/city-time-weather/pom.xml
+++ b/tutorials/city-time-weather/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>com.google.adk</groupId>
     <artifactId>google-adk-parent</artifactId>
-    <version>1.12.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
+    <version>1.12.1</version><!-- {x-version-update:google-adk:current} -->
     <relativePath>../../pom.xml</relativePath>
   </parent>
 
diff --git a/tutorials/live-audio-single-agent/pom.xml b/tutorials/live-audio-single-agent/pom.xml
index 2154d7d29..1525cad98 100644
--- a/tutorials/live-audio-single-agent/pom.xml
+++ b/tutorials/live-audio-single-agent/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>com.google.adk</groupId>
     <artifactId>google-adk-parent</artifactId>
-    <version>1.12.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
+    <version>1.12.1</version><!-- {x-version-update:google-adk:current} -->
     <relativePath>../../pom.xml</relativePath>
   </parent>