refactor: enrich description with context before calling Agent Generator (#11932)

## Summary
Updates the Agent Generator client to enrich the description with
context before calling, instead of sending `user_instruction` as a
separate parameter.

## Context
Companion PR to Significant-Gravitas/AutoGPT-Agent-Generator#105 which
removes unused parameters from the decompose API.

## Changes
- Enrich `description` with `context` (e.g., clarifying question
answers) before sending
- Remove `user_instruction` from request payload

## How it works
Both input boxes and chat box work the same way - the frontend
constructs a formatted message with answers and sends it as a user
message. The backend then enriches the description with this context
before calling the external Agent Generator service.

autogpt_platform/backend/backend/api/features/chat/tools/agent_generator/service.py

@@ -139,11 +139,10 @@ async def decompose_goal_external(
     """
     client = _get_client()
 
-    # Build the request payload
-    payload: dict[str, Any] = {"description": description}
     if context:
-        # The external service uses user_instruction for additional context
-        payload["user_instruction"] = context
+        description = f"{description}\n\nAdditional context from user:\n{context}"
+
+    payload: dict[str, Any] = {"description": description}
     if library_agents:
         payload["library_agents"] = library_agents
 

autogpt_platform/backend/test/agent_generator/test_service.py

@@ -102,7 +102,7 @@ class TestDecomposeGoalExternal:
 
     @pytest.mark.asyncio
     async def test_decompose_goal_with_context(self):
-        """Test decomposition with additional context."""
+        """Test decomposition with additional context enriched into description."""
         mock_response = MagicMock()
         mock_response.json.return_value = {
             "success": True,
@@ -119,9 +119,12 @@ class TestDecomposeGoalExternal:
                 "Build a chatbot", context="Use Python"
             )
 
+        expected_description = (
+            "Build a chatbot\n\nAdditional context from user:\nUse Python"
+        )
         mock_client.post.assert_called_once_with(
             "/api/decompose-description",
-            json={"description": "Build a chatbot", "user_instruction": "Use Python"},
+            json={"description": expected_description},
         )
 
     @pytest.mark.asyncio