diff --git a/tests/test_async_tools.py b/tests/test_async_tools.py
new file mode 100644
index 0000000..a7b3bb8
--- /dev/null
+++ b/tests/test_async_tools.py
@@ -0,0 +1,100 @@
+import asyncio
+import time
+import pytest
+from unittest.mock import patch
+from src import ai_client
+from src import mcp_client
+
+@pytest.mark.asyncio
+async def test_execute_tool_calls_concurrently_timing():
+ """
+ Verifies that _execute_tool_calls_concurrently runs tools in parallel.
+ Total time should be approx 0.5s for 3 tools each taking 0.5s.
+ """
+ # 1. Setup mock tool calls (Gemini style)
+ class MockGeminiCall:
+  def __init__(self, name, args):
+   self.name = name
+   self.args = args
+
+ calls = [
+  MockGeminiCall("read_file", {"path": "file1.txt"}),
+  MockGeminiCall("read_file", {"path": "file2.txt"}),
+  MockGeminiCall("read_file", {"path": "file3.txt"}),
+ ]
+
+ # 2. Mock async_dispatch to sleep for 0.5s
+ async def mocked_async_dispatch(name, args):
+  await asyncio.sleep(0.5)
+  return f"Content of {args.get('path')}"
+
+ # 3. Mock components in ai_client/mcp_client
+ with (
+  patch("src.mcp_client.async_dispatch", side_effect=mocked_async_dispatch),
+  patch("src.mcp_client.TOOL_NAMES", ["read_file"]),
+  patch("src.ai_client._append_comms"),
+  patch("src.ai_client.events.emit")
+ ):
+  start_time = time.time()
+  
+  results = await ai_client._execute_tool_calls_concurrently(
+   calls=calls,
+   base_dir=".",
+   pre_tool_callback=None,
+   qa_callback=None,
+   r_idx=0,
+   provider="gemini"
+  )
+  
+  end_time = time.time()
+  duration = end_time - start_time
+  
+  # 4. Assertions
+  assert len(results) == 3
+  # Parallel execution: duration should be < 1.0s (0.5s + overhead)
+  # Serial execution: duration would be >= 1.5s
+  print(f"Concurrent tool execution took {duration:.4f} seconds")
+  assert duration < 1.0, f"Tools executed serially? Took {duration:.4f}s"
+  assert duration >= 0.5, "Tools didn't even sleep?"
+
+  # Verify results content
+  for i, (name, call_id, out, orig_name) in enumerate(results):
+   assert name == "read_file"
+   assert out == f"Content of file{i+1}.txt"
+
+@pytest.mark.asyncio
+async def test_execute_tool_calls_concurrently_exception_handling():
+ """
+ Verifies that if one tool call fails, it doesn't crash the whole group if caught,
+ but currently gather is used WITHOUT return_exceptions=True, so it should re-raise.
+ """
+ class MockGeminiCall:
+  def __init__(self, name, args):
+   self.name = name
+   self.args = args
+
+ calls = [
+  MockGeminiCall("read_file", {"path": "success.txt"}),
+  MockGeminiCall("read_file", {"path": "fail.txt"}),
+ ]
+
+ async def mocked_async_dispatch(name, args):
+  if args.get("path") == "fail.txt":
+   raise ValueError("Simulated tool failure")
+  return "Success"
+
+ with (
+  patch("src.mcp_client.async_dispatch", side_effect=mocked_async_dispatch),
+  patch("src.mcp_client.TOOL_NAMES", ["read_file"]),
+  patch("src.ai_client._append_comms"),
+  patch("src.ai_client.events.emit")
+ ):
+  with pytest.raises(ValueError, match="Simulated tool failure"):
+   await ai_client._execute_tool_calls_concurrently(
+    calls=calls,
+    base_dir=".",
+    pre_tool_callback=None,
+    qa_callback=None,
+    r_idx=0,
+    provider="gemini"
+   )