diff --git a/src/commonMain/kotlin/message/Messages.kt b/src/commonMain/kotlin/message/Messages.kt
index 73ccd41..6d44d73 100644
--- a/src/commonMain/kotlin/message/Messages.kt
+++ b/src/commonMain/kotlin/message/Messages.kt
@@ -2,12 +2,7 @@ package com.xemantic.anthropic.message
 
 import com.xemantic.anthropic.schema.JsonSchema
 import com.xemantic.anthropic.tool.UsableTool
-import kotlinx.serialization.ExperimentalSerializationApi
-import kotlinx.serialization.InternalSerializationApi
-import kotlinx.serialization.KSerializer
-import kotlinx.serialization.SerialName
-import kotlinx.serialization.Serializable
-import kotlinx.serialization.SerializationException
+import kotlinx.serialization.*
 import kotlinx.serialization.builtins.serializer
 import kotlinx.serialization.descriptors.PolymorphicKind
 import kotlinx.serialization.descriptors.SerialDescriptor
@@ -16,7 +11,7 @@ import kotlinx.serialization.encoding.Decoder
 import kotlinx.serialization.encoding.Encoder
 import kotlinx.serialization.json.JsonClassDiscriminator
 import kotlinx.serialization.json.JsonDecoder
-import kotlinx.serialization.serializerOrNull
+import kotlinx.serialization.json.JsonObject
 import kotlin.collections.mutableListOf
 import kotlin.reflect.KClass
 
@@ -282,14 +277,8 @@ data class ToolUse(
   override val cacheControl: CacheControl? = null,
   val id: String,
   val name: String,
-  val input: UsableTool
-) : Content() {
-
-  fun use(): ToolResult = input.use(
-    toolUseId = id
-  )
-
-}
+  val input: JsonObject
+) : Content()
 
 @Serializable
 @SerialName("tool_result")
diff --git a/src/commonMain/kotlin/schema/JsonSchemaGenerator.kt b/src/commonMain/kotlin/schema/JsonSchemaGenerator.kt
index 5e1968e..71ef76a 100644
--- a/src/commonMain/kotlin/schema/JsonSchemaGenerator.kt
+++ b/src/commonMain/kotlin/schema/JsonSchemaGenerator.kt
@@ -5,6 +5,10 @@ import kotlinx.serialization.descriptors.*
 import kotlin.collections.set
 import kotlin.reflect.KClass
 
+inline fun <reified T> jsonSchemaOf(): JsonSchema = generateSchema(
+  serializer<T>().descriptor
+)
+
 @OptIn(InternalSerializationApi::class)
 fun KClass<*>.toJsonSchema(): JsonSchema = generateSchema(
   serializer().descriptor
diff --git a/src/commonMain/kotlin/tool/Tools.kt b/src/commonMain/kotlin/tool/Tools.kt
index ab3482b..a546dff 100644
--- a/src/commonMain/kotlin/tool/Tools.kt
+++ b/src/commonMain/kotlin/tool/Tools.kt
@@ -1,11 +1,14 @@
 package com.xemantic.anthropic.tool
 
+import com.xemantic.anthropic.anthropicJson
 import com.xemantic.anthropic.message.CacheControl
 import com.xemantic.anthropic.message.Tool
 import com.xemantic.anthropic.message.ToolResult
+import com.xemantic.anthropic.message.ToolUse
 import com.xemantic.anthropic.schema.toJsonSchema
 import kotlinx.serialization.ExperimentalSerializationApi
 import kotlinx.serialization.InternalSerializationApi
+import kotlinx.serialization.KSerializer
 import kotlinx.serialization.json.JsonClassDiscriminator
 import kotlinx.serialization.modules.SerializersModule
 import kotlinx.serialization.modules.polymorphic
@@ -16,7 +19,7 @@ annotation class Description(
   val value: String
 )
 
-@JsonClassDiscriminator("type")
+@JsonClassDiscriminator("name")
 @OptIn(ExperimentalSerializationApi::class)
 //@Serializable(with = UsableToolSerializer::class)
 interface UsableTool {
@@ -27,6 +30,10 @@ interface UsableTool {
 
 }
 
+class ToolContentSerializer() {
+
+}
+
 @OptIn(InternalSerializationApi::class, ExperimentalSerializationApi::class)
 fun <T : UsableTool> KClass<T>.verify() {
   // TODO how to get class serializer correctly?
@@ -72,3 +79,12 @@ fun <T : UsableTool> List<KClass<T>>.toSerializersModule(): SerializersModule =
 //  inputSchema = jsonSchemaOf<T>(),
 //  cacheControl = cacheControl
 //)
+
+
+fun <T : UsableTool> ToolUse.use(
+  map: Map<String, KSerializer<T>>
+): ToolResult {
+  val serializer = map[name]!!
+  val tool = anthropicJson.decodeFromJsonElement(serializer, input)
+  return tool.use(toolUseId = id)
+}
diff --git a/src/commonTest/kotlin/AnthropicTest.kt b/src/commonTest/kotlin/AnthropicTest.kt
index d827cf7..aac76b5 100644
--- a/src/commonTest/kotlin/AnthropicTest.kt
+++ b/src/commonTest/kotlin/AnthropicTest.kt
@@ -9,6 +9,7 @@ import com.xemantic.anthropic.message.Role
 import com.xemantic.anthropic.message.StopReason
 import com.xemantic.anthropic.message.Text
 import com.xemantic.anthropic.message.ToolUse
+import com.xemantic.anthropic.tool.use
 import kotlinx.coroutines.flow.filterIsInstance
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.toList
diff --git a/src/commonTest/kotlin/message/MessagesTest.kt b/src/commonTest/kotlin/message/MessagesTest.kt
index 67a9410..43cab02 100644
--- a/src/commonTest/kotlin/message/MessagesTest.kt
+++ b/src/commonTest/kotlin/message/MessagesTest.kt
@@ -1,7 +1,8 @@
 package com.xemantic.anthropic.message
 
+import com.xemantic.anthropic.Calculator
 import com.xemantic.anthropic.anthropicJson
-import com.xemantic.anthropic.testToolsSerializersModule
+import com.xemantic.anthropic.tool.toSerializersModule
 import io.kotest.assertions.json.shouldEqualJson
 import kotlinx.serialization.ExperimentalSerializationApi
 import kotlinx.serialization.encodeToString
@@ -20,7 +21,7 @@ class MessagesTest {
     prettyPrint = true
     @OptIn(ExperimentalSerializationApi::class)
     prettyPrintIndent = "  "
-    serializersModule = testToolsSerializersModule
+    //serializersModule = testToolsSerializersModule
   }
 
   @Test
@@ -59,6 +60,9 @@ class MessagesTest {
 
   @Test
   fun shouldDeserializeToolUseRequest() {
+    val json = Json(from = json) {
+      serializersModule = listOf(Calculator::class).toSerializersModule()
+    }
     val request = """
       {
         "id": "msg_01PspkNzNG3nrf5upeTsmWLF",