fix: preserve empty tools array from server instead of coercing to None

Co-Authored-By: Paul Loeb <ploeb@launchdarkly.com>

Author: devin-ai-integration[bot]

packages/sdk/server-ai/src/ldai/client.py

@@ -69,14 +69,14 @@ def _completion_config(
                 )
                 for tool in variation['tools']
                 if isinstance(tool, dict) and 'key' in tool
-            ] or None
+            ]
 
         config = AICompletionConfig(
             key=key,
             enabled=bool(enabled),
             model=model,
             messages=messages,
-            tools=tools if tools is not None else (default.tools if default.tools else None),
+            tools=tools if tools is not None else default.tools,
             provider=provider,
             tracker=tracker,
             judge_configuration=judge_configuration,
@@ -742,15 +742,15 @@ def __evaluate_agent(
                 )
                 for tool in variation['tools']
                 if isinstance(tool, dict) and 'key' in tool
-            ] or None
+            ]
 
         return AIAgentConfig(
             key=key,
             enabled=bool(enabled) if enabled is not None else (default.enabled or False),
             model=model or default.model,
             provider=provider or default.provider,
             instructions=final_instructions,
-            tools=tools if tools is not None else (default.tools if default.tools else None),
+            tools=tools if tools is not None else default.tools,
             tracker=tracker,
             judge_configuration=judge_configuration or default.judge_configuration,
         )

packages/sdk/server-ai/tests/test_tools.py

@@ -207,14 +207,34 @@ def test_completion_config_without_tools(ldai_client: LDAIClient):
 
 
 def test_completion_config_empty_tools(ldai_client: LDAIClient):
-    """Test that completion config handles empty tools array."""
+    """Test that completion config preserves empty tools array from server."""
     context = Context.create('user-key')
     default = AICompletionConfigDefault(enabled=False, model=ModelConfig('fallback'))
 
     config = ldai_client.completion_config('empty-tools-config', context, default)
 
     assert config.enabled is True
-    assert config.tools is None
+    # An explicit empty tools array from server should be preserved as empty list,
+    # NOT fall back to defaults
+    assert config.tools is not None
+    assert config.tools == []
+
+
+def test_completion_config_empty_tools_no_default_fallback(ldai_client: LDAIClient):
+    """Test that empty tools array from server does NOT fall back to defaults."""
+    context = Context.create('user-key')
+    default_tools = [AITool(key='default-tool', version=1)]
+    default = AICompletionConfigDefault(
+        enabled=False,
+        model=ModelConfig('fallback'),
+        tools=default_tools,
+    )
+
+    config = ldai_client.completion_config('empty-tools-config', context, default)
+
+    assert config.enabled is True
+    # Server sent empty tools=[], so we should honor that, not use defaults
+    assert config.tools == []
 
 
 def test_completion_config_uses_default_tools(ldai_client: LDAIClient):