diff --git a/ext/mcp/src/internal-test.rs b/ext/mcp/src/internal-test.rs
index 56867e4..8821ddd 100644
--- a/ext/mcp/src/internal-test.rs
+++ b/ext/mcp/src/internal-test.rs
@@ -9,12 +9,12 @@ use jsonrpsee::core::traits::ToRpcParams;
 use tokio::process::{Child, ChildStdin, ChildStdout};
 use tokio::io::{AsyncBufReadExt, AsyncReadExt, AsyncWriteExt, BufReader};
 use serde::{Deserialize, Serialize};
-use serde_json::Error;
+use serde_json::{json, Error};
 use serde_json::value::RawValue;
 use tokio::time::sleep;
 use tracing::debug;
 use types::{Implementation, InitializeRequestParams, InitializeResult};
-use crate::types::{ClientCapabilities, ListToolsRequestParams, ListToolsResult};
+use crate::types::{CallToolRequestParams, ClientCapabilities, ListToolsRequestParams, ListToolsResult};
 
 mod types;
 
@@ -69,6 +69,16 @@ impl<T: Serialize> ToRpcParams for RpcArg<T> {
     }
 }
 
+trait ToRpcArg: Sized {
+    fn to_rpc(self) -> RpcArg<Self>;
+}
+
+impl<T: Serialize> ToRpcArg for &T {
+    fn to_rpc(self) -> RpcArg<Self> {
+        RpcArg(self)
+    }
+}
+
 struct NoParams;
 
 impl ToRpcParams for NoParams {
@@ -101,17 +111,21 @@ async fn main() -> anyhow::Result<()> {
         transport.clone(),
     );
 
-    let response: InitializeResult = client.request("initialize", RpcArg(InitializeRequestParams {
+    let response: InitializeResult = client.request("initialize", InitializeRequestParams {
         capabilities: ClientCapabilities::default(),
         client_info: Implementation { name: "Rust MCP".to_string(), version: "0.1.0".to_string() },
         protocol_version: "2024-11-05".to_string(),
-    })).await?;
-
-    println!("Response: {:?}", response);
+    }.to_rpc()).await?;
 
     client.notification("notifications/initialized", NoParams).await?;
 
-    let response: ListToolsResult = client.request("tools/list", RpcArg(ListToolsRequestParams::default())).await?;
+    let response: ListToolsResult = client.request("tools/list", ListToolsRequestParams::default().to_rpc()).await?;
+
+    let response: serde_json::Value = client.request("tools/call", CallToolRequestParams {
+        arguments: json!({ "url": "http://example.com" }).as_object().unwrap().clone(),
+        name: "fetch".to_string(),
+    }.to_rpc()).await?;
+
     println!("Response: {:#?}", response);
 
     Ok(())