Chatty LLMs should pipe down

.github/copilot-instructions.md

@@ -196,6 +196,7 @@ firmware/
 - Prefer `LOG_DEBUG`, `LOG_INFO`, `LOG_WARN`, `LOG_ERROR` for logging
 - Use `assert()` for invariants that should never fail
 - C++17 features are available (`std::optional`, structured bindings, `if constexpr`, etc.)
+- **Keep code comments minimal — one or two lines, max.** Comment only when the _why_ isn't obvious from the code; never restate what the next line does. No multi-paragraph block comments explaining straightforward changes. The diff and commit message carry the rationale; the code carries the behavior.
 
 ### Naming Conventions
 

AGENTS.md

@@ -66,6 +66,7 @@ Key rotation to never trigger casually: only the **full** factory reset (`factor
 - **Don't speculate about firmware root causes.** When evidence doesn't support a classification, say "unknown" and list what would disambiguate.
 - **Run `trunk fmt` before proposing a commit.** The `trunk_check` CI gate will reject unformatted code.
 - **`confirm=True` on destructive MCP tools is a real gate, not a formality.** Don't bypass it via auto-approve settings.
+- **Keep code comments minimal — one or two lines, max.** Comment only when the _why_ isn't obvious from the code; never restate what the next line does. No multi-paragraph block comments explaining straightforward changes. The diff and commit message carry the rationale; the code carries the behavior.
 
 ## Typical agent workflows