[autoresearch] baseline: system prompt quality tests (5/5 passing)

.agents/rules/concurrency-and-threading-mandate.md

@@ -0,0 +1,25 @@
+---
+trigger: always_on
+---
+
+## Concurrency and Threading Mandate
+
+### When to Use Concurrency
+
+**I/O-Bound Operations:** Use asynchronous I/O, event-driven concurrency, or coroutines when waiting on network requests, file I/O, or database queries.
+
+**CPU-Bound Operations:** Use OS threads or thread pools for heavy computation, data processing, or encoding work where CPU cycles dominate.
+
+**Don't Over-Use Concurrency:** Concurrency adds significant complexity (race conditions, deadlocks, debugging difficulty). Profile first — only add concurrency when there is a measurable performance benefit.
+
+For implementation details (race condition prevention, deadlock avoidance, message passing patterns), see Concurrency and Threading Principles @concurrency-and-threading-principles.md.
+
+### When NOT to Use Concurrency
+- Simple synchronous operations
+- No measurable performance benefit
+- Avoid premature optimization
+
+### Related Principles
+- Concurrency and Threading Principles @concurrency-and-threading-principles.md
+- Performance Optimization Principles @performance-optimization-principles.md
+- Rust Idioms and Patterns @rust-idioms-and-patterns.md