style: clarify built-in tool extraction rationale

Author: ndycode

lib/request/request-transformer.ts

@@ -421,6 +421,8 @@ function extractRuntimeToolNames(tools: unknown): string[] {
 	for (const tool of tools) {
 		if (!tool || typeof tool !== "object") continue;
 
+		// Pure in-memory name extraction only: no filesystem I/O, token access,
+		// or logging side effects are introduced by recognizing built-in tool types.
 		const toolType = (tool as { type?: unknown }).type;
 		if (typeof toolType === "string" && toolType.trim() && toolType !== "function") {
 			names.push(toolType);

test/request-transformer.test.ts

@@ -772,7 +772,7 @@ describe('Request Transformer Module', () => {
 		});
 	});
 
-		describe('transformRequestBody', () => {
+	describe('transformRequestBody', () => {
 			const codexInstructions = 'Test Codex Instructions';
 
 			it('preserves existing prompt_cache_key passed by host (OpenCode)', async () => {