Fix connector FastMCP tool calls

- use fastmcp call_tool with meta fallback instead of call_tool_mcp
- normalize results to mcp CallToolResult and update connector test

Author: ryantzr1

hud/environment/connection.py

@@ -4,7 +4,7 @@
 
 import logging
 from enum import Enum
-from typing import TYPE_CHECKING, Any
+from typing import TYPE_CHECKING, Any, cast
 
 import mcp.types as mcp_types
 
@@ -200,10 +200,31 @@ async def call_tool(
         trace_id = get_current_trace_id()
         meta = {"_hud_trace_id": trace_id} if trace_id else None
 
+        client = cast(Any, self.client)
         try:
-            return await self.client.call_tool_mcp(name, args, _meta=meta)
+            result = await client.call_tool(name=name, arguments=args, _meta=meta)
         except TypeError:
-            return await self.client.call_tool_mcp(name, args)
+            # Fallback for clients that don't accept _meta
+            result = await client.call_tool(name=name, arguments=args)
+
+        # FastMCP and mcp-python use slightly different result shapes/types.
+        # Normalize to mcp.types.CallToolResult for the rest of HUD.
+        is_error = getattr(result, "isError", None)
+        if is_error is None:
+            is_error = getattr(result, "is_error", False)
+        structured = getattr(result, "structuredContent", None)
+        if structured is None:
+            structured = getattr(result, "structured_content", None)
+
+        content = getattr(result, "content", None)
+        if content is None:
+            content = []
+
+        return mcp_types.CallToolResult(
+            content=content,
+            isError=bool(is_error),
+            structuredContent=structured,
+        )
 
     async def list_resources(self) -> list[mcp_types.Resource]:
         """Fetch resources from server and cache.

hud/environment/tests/test_connection.py

@@ -281,13 +281,15 @@ async def test_call_tool_strips_prefix(self) -> None:
 
         mock_result = mcp_types.CallToolResult(content=[], isError=False)
         mock_client = MagicMock()
-        mock_client.call_tool_mcp = AsyncMock(return_value=mock_result)
+        mock_client.call_tool = AsyncMock(return_value=mock_result)
         connector.client = mock_client
 
         await connector.call_tool("myprefix_tool1", {"arg": "value"})
 
         # Prefix should be stripped
-        mock_client.call_tool_mcp.assert_called_once_with("tool1", {"arg": "value"})
+        mock_client.call_tool.assert_called_once_with(
+            name="tool1", arguments={"arg": "value"}, _meta=None
+        )
 
     @pytest.mark.asyncio
     async def test_call_tool_raises_when_not_connected(self) -> None: