diff --git a/sdk/packages/core/src/extensions/context/basic-compaction.ts b/sdk/packages/core/src/extensions/context/basic-compaction.ts
index cd8405c989..9858943ffb 100644
--- a/sdk/packages/core/src/extensions/context/basic-compaction.ts
+++ b/sdk/packages/core/src/extensions/context/basic-compaction.ts
@@ -397,6 +397,9 @@ export function runBasicCompaction(options: {
 		policyIntent: "basic_compaction_projection",
 		estimateMessageTokens: options.estimateMessageTokens,
 	});
+	// This final projection owns the hard output budget. Unlike the earlier
+	// basic candidate passes, it may drop the original first-user message when
+	// preserving the latest typed prompt and coherent tool closures requires it.
 	if (budgeted.status === "failed") {
 		options.logger?.debug("Basic compaction returned best-effort projection", {
 			budgetWarnings: budgeted.warnings.map((warning) => warning.code),
@@ -428,6 +431,7 @@ export function runBasicCompaction(options: {
 		messagesRemoved: options.context.messages.length - resultMessages.length,
 		tokensBefore: beforeTokens,
 		tokensAfter: afterTokens,
+		budgetStatus: budgeted.status,
 		budgetActions: budgeted.actions.length,
 		budgetWarnings: budgeted.warnings.map((warning) => warning.code),
 		targetTokens,