fix: Update list_agents to only list directories, not validate agent definitions

The list_agents method in AgentLoader no longer attempts to determine the agent language for each directory

Co-authored-by: George Weale <gweale@google.com>
PiperOrigin-RevId: 890078066

Author: GWeale

src/google/adk/cli/utils/agent_loader.py

@@ -364,18 +364,13 @@ def load_agent(self, agent_name: str) -> Union[BaseAgent, App]:
   def list_agents(self) -> list[str]:
     """Lists all agents available in the agent loader (sorted alphabetically)."""
     base_path = Path.cwd() / self.agents_dir
-    agent_names = []
-    for x in os.listdir(base_path):
-      if (
-          os.path.isdir(os.path.join(base_path, x))
-          and not x.startswith(".")
-          and x != "__pycache__"
-      ):
-        try:
-          self._determine_agent_language(x)
-          agent_names.append(x)
-        except ValueError:
-          continue
+    agent_names = [
+        x
+        for x in os.listdir(base_path)
+        if os.path.isdir(os.path.join(base_path, x))
+        and not x.startswith(".")
+        and x != "__pycache__"
+    ]
     agent_names.sort()
     return agent_names
 

tests/unittests/cli/utils/test_agent_loader.py

@@ -960,51 +960,6 @@ def __init__(self):
       assert detailed_list[0]["name"] == agent_name
       assert not detailed_list[0]["is_computer_use"]
 
-  def test_list_agents_excludes_non_agent_directories(self):
-    """Test that list_agents filters out directories without agent definitions."""
-    with tempfile.TemporaryDirectory() as temp_dir:
-      temp_path = Path(temp_dir)
-
-      valid_package = temp_path / "valid_agent"
-      valid_package.mkdir()
-      (valid_package / "__init__.py").write_text(dedent("""
-          from google.adk.agents.base_agent import BaseAgent
-
-          class ValidAgent(BaseAgent):
-              def __init__(self):
-                  super().__init__(name="valid_agent")
-
-          root_agent = ValidAgent()
-      """))
-
-      valid_module = temp_path / "module_agent"
-      valid_module.mkdir()
-      (valid_module / "agent.py").write_text(dedent("""
-          from google.adk.agents.base_agent import BaseAgent
-
-          class ModuleAgent(BaseAgent):
-              def __init__(self):
-                  super().__init__(name="module_agent")
-
-          root_agent = ModuleAgent()
-      """))
-
-      valid_yaml = temp_path / "yaml_agent"
-      valid_yaml.mkdir()
-      (valid_yaml / "root_agent.yaml").write_text("name: yaml_agent\n")
-
-      (temp_path / "random_folder").mkdir()
-      (temp_path / "data").mkdir()
-      (temp_path / "tmp").mkdir()
-
-      loader = AgentLoader(str(temp_path))
-      agents = loader.list_agents()
-
-      assert agents == ["module_agent", "valid_agent", "yaml_agent"]
-      assert "random_folder" not in agents
-      assert "data" not in agents
-      assert "tmp" not in agents
-
   def test_validate_agent_name_rejects_dotted_paths(self):
     """Agent names with dots are rejected to prevent arbitrary module imports."""
     with tempfile.TemporaryDirectory() as temp_dir: