Fix parsing of tools with missing docstring descriptions

src/serena/mcp.py

@@ -61,7 +61,10 @@ def make_tool(
 
     # Mount the tool description as a combination of the docstring description and
     # the return value description, if it exists.
-    func_doc = f"{docstring.description.strip().strip('.')}."
+    if docstring.description:
+        func_doc = f"{docstring.description.strip().strip('.')}."
+    else:
+        func_doc = "No description available."
     if (docstring.returns) and (docstring_returns := docstring.returns.description):
         func_doc = f"{func_doc} Returns {docstring_returns.strip().strip('.')}."
 

test/serena/test_mcp.py

@@ -198,3 +198,65 @@ def test_make_tool_missing_apply() -> None:
 
     with pytest.raises(AttributeError):
         make_tool(tool)
+
+
+def test_make_tool_missing_description() -> None:
+    """Test make_tool with a function that has no description in the docstring."""
+
+    class NoDescriptionTool(BaseMockTool):
+        def apply(self, param: str) -> str:
+            """
+            :param param: The parameter
+            :return: A result
+            """
+            return f"Result: {param}"
+
+        def apply_ex(self, *args, **kwargs) -> str:
+            return self.apply(**kwargs)
+
+    tool = NoDescriptionTool()
+    mcp_tool = make_tool(tool)
+
+    assert mcp_tool.name == "no_description"
+    assert mcp_tool.description == "No description available. Returns A result."
+    assert mcp_tool.parameters["properties"]["param"]["description"] == "The parameter."
+
+
+def test_make_tool_all_tools() -> None:
+    """Test that make_tool works for all tools in the codebase."""
+    from serena.agent import iter_tool_classes, Tool
+
+    # Create a mock agent for tool initialization
+    class MockAgent:
+        def __init__(self):
+            self.project_config = None
+            self.serena_config = None
+
+    # Get all tool classes
+    tool_classes = list(iter_tool_classes())
+    
+    # Make sure we found some tools
+    assert len(tool_classes) > 0
+    
+    # Test each tool class
+    for tool_class in tool_classes:
+        try:
+            # Skip abstract base classes that can't be instantiated
+            if tool_class.__name__ == "Tool" or getattr(tool_class, "__abstractmethods__", set()):
+                continue
+                
+            # Create an instance of the tool
+            tool_instance = tool_class(MockAgent())
+            
+            # Try to create an MCP tool from it
+            mcp_tool = make_tool(tool_instance)
+            
+            # Basic validation
+            assert isinstance(mcp_tool, MCPTool)
+            assert mcp_tool.name == tool_class.get_name()
+            
+            # The description should be a string (either from docstring or default)
+            assert isinstance(mcp_tool.description, str)
+            
+        except Exception as e:
+            pytest.fail(f"Failed to create MCP tool for {tool_class.__name__}: {e}")