fix: Add defensive validation and fix test import path

- Add validation for nested dictionary keys to prevent KeyError
- Add JSON serialization validation to ensure tools are serializable  
- Fix import path in test_async_tool_formats.py
- Improves robustness of tool formatting

Co-authored-by: Mervin Praison <MervinPraison@users.noreply.github.com>

Author: claude[bot]

src/praisonai-agents/praisonaiagents/llm/llm.py

@@ -386,14 +386,22 @@ def _format_tools_for_litellm(self, tools: Optional[List[Any]]) -> Optional[List
         for tool in tools:
             # Check if the tool is already in OpenAI format (e.g. from MCP.to_openai_tool())
             if isinstance(tool, dict) and 'type' in tool and tool['type'] == 'function':
-                logging.debug(f"Using pre-formatted OpenAI tool: {tool['function']['name']}")
-                formatted_tools.append(tool)
+                # Validate nested dictionary structure before accessing
+                if 'function' in tool and isinstance(tool['function'], dict) and 'name' in tool['function']:
+                    logging.debug(f"Using pre-formatted OpenAI tool: {tool['function']['name']}")
+                    formatted_tools.append(tool)
+                else:
+                    logging.debug(f"Skipping malformed OpenAI tool: missing function or name")
             # Handle lists of tools (e.g. from MCP.to_openai_tool())
             elif isinstance(tool, list):
                 for subtool in tool:
                     if isinstance(subtool, dict) and 'type' in subtool and subtool['type'] == 'function':
-                        logging.debug(f"Using pre-formatted OpenAI tool from list: {subtool['function']['name']}")
-                        formatted_tools.append(subtool)
+                        # Validate nested dictionary structure before accessing
+                        if 'function' in subtool and isinstance(subtool['function'], dict) and 'name' in subtool['function']:
+                            logging.debug(f"Using pre-formatted OpenAI tool from list: {subtool['function']['name']}")
+                            formatted_tools.append(subtool)
+                        else:
+                            logging.debug(f"Skipping malformed OpenAI tool in list: missing function or name")
             elif callable(tool):
                 tool_def = self._generate_tool_definition(tool.__name__)
                 if tool_def:
@@ -405,6 +413,15 @@ def _format_tools_for_litellm(self, tools: Optional[List[Any]]) -> Optional[List
             else:
                 logging.debug(f"Skipping tool of unsupported type: {type(tool)}")
 
+        # Validate JSON serialization before returning
+        if formatted_tools:
+            try:
+                import json
+                json.dumps(formatted_tools)  # Validate serialization
+            except (TypeError, ValueError) as e:
+                logging.error(f"Tools are not JSON serializable: {e}")
+                return None
+                
         return formatted_tools if formatted_tools else None
 
     def get_response(

src/praisonai/tests/unit/test_async_tool_formats.py

@@ -9,7 +9,7 @@
 from typing import Dict, List, Optional
 
 # Add the source directory to path
-sys.path.insert(0, os.path.join(os.path.dirname(__file__), 'src/praisonai-agents'))
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '../../../praisonai-agents'))
 
 from praisonaiagents.llm import LLM