diff --git a/gui.py b/gui.py
index d509840..29ad951 100644
--- a/gui.py
+++ b/gui.py
@@ -501,6 +501,7 @@ class App:
         ai_client.confirm_and_run_callback = self._confirm_and_run
         ai_client.comms_log_callback = self._on_comms_entry
         ai_client.tool_log_callback = self._on_tool_log
+        mcp_client.perf_monitor_callback = self.perf_monitor.get_metrics
 
     # ---------------------------------------------------------------- project loading
 
diff --git a/mcp_client.py b/mcp_client.py
index 6879729..7fccf53 100644
--- a/mcp_client.py
+++ b/mcp_client.py
@@ -45,6 +45,9 @@ _allowed_paths: set[Path] = set()
 _base_dirs: set[Path] = set()
 _primary_base_dir: Path | None = None
 
+# Injected by gui.py - returns a dict of performance metrics
+perf_monitor_callback = None
+
 
 def configure(file_items: list[dict], extra_base_dirs: list[str] | None = None):
     """
@@ -300,11 +303,27 @@ def fetch_url(url: str) -> str:
         return full_text
     except Exception as e:
         return f"ERROR fetching URL '{url}': {e}"
+    
+    
+def get_ui_performance() -> str:
+    """Returns current UI performance metrics (FPS, Frame Time, CPU, Input Lag)."""
+    if perf_monitor_callback is None:
+        return "ERROR: Performance monitor callback not registered."
+    try:
+        metrics = perf_monitor_callback()
+        # Clean up the dict string for the AI
+        metric_str = str(metrics)
+        for char in "{}'":
+            metric_str = metric_str.replace(char, "")
+        return f"UI Performance Snapshot:\n{metric_str}"
+    except Exception as e:
+        return f"ERROR: Failed to retrieve UI performance: {str(e)}"
+
 
 # ------------------------------------------------------------------ tool dispatch
 
 
-TOOL_NAMES = {"read_file", "list_directory", "search_files", "get_file_summary", "web_search", "fetch_url"}
+TOOL_NAMES = {"read_file", "list_directory", "search_files", "get_file_summary", "web_search", "fetch_url", "get_ui_performance"}
 
 
 def dispatch(tool_name: str, tool_input: dict) -> str:
@@ -323,6 +342,8 @@ def dispatch(tool_name: str, tool_input: dict) -> str:
         return web_search(tool_input.get("query", ""))
     if tool_name == "fetch_url":
         return fetch_url(tool_input.get("url", ""))
+    if tool_name == "get_ui_performance":
+        return get_ui_performance()
     return f"ERROR: unknown MCP tool '{tool_name}'"
 
 
@@ -420,17 +441,11 @@ MCP_TOOL_SPECS = [
         }
     },
     {
-        "name": "fetch_url",
-        "description": "Fetch a webpage and extract its text content, removing HTML tags and scripts. Useful for reading documentation or articles found via web_search.",
+        "name": "get_ui_performance",
+        "description": "Get a snapshot of the current UI performance metrics, including FPS, Frame Time (ms), CPU usage (%), and Input Lag (ms). Use this to diagnose UI slowness or verify that your changes haven't degraded the user experience.",
         "parameters": {
             "type": "object",
-            "properties": {
-                "url": {
-                    "type": "string",
-                    "description": "The URL to fetch."
-                }
-            },
-            "required": ["url"]
+            "properties": {}
         }
-    },
+    }
 ]
diff --git a/tests/test_mcp_perf_tool.py b/tests/test_mcp_perf_tool.py
new file mode 100644
index 0000000..105a8cd
--- /dev/null
+++ b/tests/test_mcp_perf_tool.py
@@ -0,0 +1,32 @@
+import unittest
+from unittest.mock import MagicMock
+import mcp_client
+
+class TestMCPPerfTool(unittest.TestCase):
+    def test_get_ui_performance_dispatch(self):
+        # Mock the callback
+        mock_metrics = {
+            'last_frame_time_ms': 16.6,
+            'fps': 60.0,
+            'cpu_percent': 15.5,
+            'input_lag_ms': 5.0
+        }
+        mcp_client.perf_monitor_callback = MagicMock(return_value=mock_metrics)
+        
+        # Test dispatch
+        result = mcp_client.dispatch("get_ui_performance", {})
+        
+        self.assertIn("UI Performance Snapshot:", result)
+        self.assertIn("last_frame_time_ms: 16.6", result)
+        self.assertIn("fps: 60.0", result)
+        self.assertIn("cpu_percent: 15.5", result)
+        self.assertIn("input_lag_ms: 5.0", result)
+        
+        mcp_client.perf_monitor_callback.assert_called_once()
+
+    def test_tool_spec_exists(self):
+        spec_names = [spec["name"] for spec in mcp_client.MCP_TOOL_SPECS]
+        self.assertIn("get_ui_performance", spec_names)
+
+if __name__ == '__main__':
+    unittest.main()