docs: tool investigation report from awesome-ai-tools (#926)

fix: restore _format_error helper for test compatibility (#916)

docs/tool-investigation-report.md

@@ -0,0 +1,24 @@
+# Tool Investigation Report: Top 5 Recommendations
+
+**Generated:** 2026-04-20 | **Source:** formatho/awesome-ai-tools (795 tools, 10 categories)
+
+## Top 5
+
+1. **LiteLLM** (76k) — Unified API gateway. Replace custom provider routing. Impact: 5/5, Effort: 2/5
+2. **Mem0** (53k) — Universal memory layer. Structured long-term memory. Impact: 5/5, Effort: 3/5
+3. **RAGFlow** (77k) — RAG engine with OCR. Document processing upgrade. Impact: 4/5, Effort: 4/5
+4. **LiteRT-LM** (3.7k) — On-device inference. Edge/mobile deployment. Impact: 4/5, Effort: 3/5
+5. **Claude-Mem** (61k) — Session capture and context injection. Impact: 3/5, Effort: 2/5
+
+## Priority
+
+- Phase 1: LiteLLM (2-3 days, highest ROI)
+- Phase 2: Mem0 (1 week, critical for agent maturity)
+- Phase 3: RAGFlow (1-2 weeks, capability upgrade)
+
+## Honorable Mentions
+
+- GPTCache: Semantic cache, 30-50% cost reduction
+- promptfoo: LLM testing framework
+- PageIndex: Vectorless RAG
+- rtk: Token reduction proxy, 60-90% savings

tools/skill_manager_tool.py

@@ -44,6 +44,34 @@ from typing import Dict, Any, Optional, Tuple
 
 logger = logging.getLogger(__name__)
 
+
+def _format_error(
+    message: str,
+    skill_name: str = None,
+    file_path: str = None,
+    suggestion: str = None,
+    context: dict = None,
+) -> Dict[str, Any]:
+    """Format an error with rich context for better debugging."""
+    parts = [message]
+    if skill_name:
+        parts.append(f"Skill: {skill_name}")
+    if file_path:
+        parts.append(f"File: {file_path}")
+    if suggestion:
+        parts.append(f"Suggestion: {suggestion}")
+    if context:
+        for key, value in context.items():
+            parts.append(f"{key}: {value}")
+    return {
+        "success": False,
+        "error": " | ".join(parts),
+        "skill_name": skill_name,
+        "file_path": file_path,
+        "suggestion": suggestion,
+    }
+
+
 # Import security scanner — agent-created skills get the same scrutiny as
 # community hub installs.
 try: