chat completion, testing

# What does this PR do?


## Test Plan
# What does this PR do?


## Test Plan

llama_stack/ui/lib/format-tool-call.tsx

@@ -0,0 +1,33 @@
+/**
+ * Formats a tool_call object into a string representation.
+ * Example: "functionName(argumentsString)"
+ * @param toolCall The tool_call object, expected to have a `function` property
+ *                 with `name` and `arguments`.
+ * @returns A formatted string or an empty string if data is malformed.
+ */
+export function formatToolCallToString(toolCall: any): string {
+  if (
+    !toolCall ||
+    !toolCall.function ||
+    typeof toolCall.function.name !== "string" ||
+    toolCall.function.arguments === undefined
+  ) {
+    return "";
+  }
+
+  const name = toolCall.function.name;
+  const args = toolCall.function.arguments;
+  let argsString: string;
+
+  if (typeof args === "string") {
+    argsString = args;
+  } else {
+    try {
+      argsString = JSON.stringify(args);
+    } catch (error) {
+      return "";
+    }
+  }
+
+  return `${name}(${argsString})`;
+}