vibe.tool-fallback

# Tool Fallback Strategies ## Pre-check (K1) > Did a tool just fail? If the error is a simple typo or wrong path, fix the input first. This skill is for persistent failures (429, 5xx, timeouts). ## Circuit Breaker State Machine ``` ┌─────────┐ 3 failures ┌─────────┐ 30s cooldown ┌─────────────┐ │ CLOSED │ ─────────────→ │ OPEN │ ───────────────→ │ HALF-OPEN │ │ (normal)│ │ (block) │ │ (test 1 req)│ └─────────┘ └─────────┘ └─────────────┘ ↑ │ │ success │ └────────────────────────────────────────────────────────┘ ``` | State | Behavior | |-------|----------| | CLOSED | Normal operation, count failures | | OPEN | Skip tool immediately, use alternative | | HALF-OPEN | Allow 1 test request after cooldown | ## Decision Trees Select exactly one conditional reference for the failing capability; unrelated failures do not load it: - Web search failure → `references/web-search.md` - External LLM failure → `references/external-llm.md` - File/code lookup failure → `references/file-lookup.md` ## Error Response Actions | Error | Action | Circuit Impact | |-------|--------|---------------| | 429 Rate Limit | Skip to next alternative (don't retry) | +1 failure | | 5xx Server Error | Retry with backoff, then switch | +1 failure | | 529 Overloaded | Wait and retry once | +1 failure | | Timeout...