fix: Improve knowledge context formatting for better LLM effectiveness

- Make knowledge context more explicit and instructive for LLM
- Add clear instructions to use provided context
- Add comprehensive test coverage for knowledge utils

Fixes #2269

Co-Authored-By: Joe Moura <joao@crewai.com>

src/crewai/knowledge/utils/knowledge_utils.py

@@ -2,11 +2,19 @@ from typing import Any, Dict, List
 
 
 def extract_knowledge_context(knowledge_snippets: List[Dict[str, Any]]) -> str:
-    """Extract knowledge from the task prompt."""
+    """Extract knowledge from the task prompt and format it for effective LLM usage."""
     valid_snippets = [
         result["context"]
         for result in knowledge_snippets
         if result and result.get("context")
     ]
+    if not valid_snippets:
+        return ""
+    
     snippet = "\n".join(valid_snippets)
-    return f"Additional Information: {snippet}" if valid_snippets else ""
+    return (
+        "Important Context (You MUST use this information to complete your task "
+        "accurately and effectively):\n"
+        f"{snippet}\n\n"
+        "Make sure to incorporate the above context into your response."
+    )