diff --git a/docs/adr/53719-warn-on-stale-logs-without-date-range.md b/docs/adr/53719-warn-on-stale-logs-without-date-range.md
new file mode 100644
index 00000000000..9fd373b53ef
--- /dev/null
+++ b/docs/adr/53719-warn-on-stale-logs-without-date-range.md
@@ -0,0 +1,48 @@
+# ADR-53719: Warn Callers When `logs` MCP Tool Returns Stale Data Without a Date Range
+
+**Date**: 2026-08-18
+**Status**: Draft
+**Deciders**: pelikhan, copilot-swe-agent
+
+---
+
+### Context
+
+The `logs` MCP tool paginates workflow runs backwards by creation date until it has collected the requested count. In high-activity repositories, this walk can silently land on a window that is days or weeks old when recent non-agentic runs dominate the page. Callers that omit `start_date`/`end_date` receive stale data with no signal that more recent runs exist, causing deep-report and audit workflows to draw incorrect conclusions about current fleet health (see issue #53683).
+
+### Decision
+
+We will add a post-query staleness check (`staleLogsWarning`) that fires only when no date range was requested and the newest run in the result set is older than 48 hours. The warning is folded into the output's `message` field by `renderLogsOutput`, then extracted and surfaced verbatim in the MCP tool's top-level response text by `buildLogsFileResponse` so callers see it immediately without opening the cached file.
+
+### Alternatives Considered
+
+#### Alternative 1: Require explicit date bounds (hard rejection)
+
+Reject any `logs` call that omits both `start_date` and `end_date`, returning an error that forces the caller to specify a range.
+
+This eliminates the ambiguity entirely but is a breaking change: all existing callers that rely on the count-only invocation pattern would need to be updated simultaneously, and some legitimate use-cases (e.g., "give me the last N runs regardless of when they ran") become impossible to express.
+
+#### Alternative 2: Transparent auto-retry with a default date window
+
+Detect staleness and automatically re-issue the query with a sensible default `start_date` (e.g., `-1d`) without telling the caller.
+
+This silently fixes the common case but hides the ambiguity rather than exposing it. Callers lose visibility into the scope of their query; if the auto-selected window is wrong for a given repo's cadence, results are still wrong—and now there is no warning to prompt investigation.
+
+### Consequences
+
+#### Positive
+- Callers receive an actionable warning in the MCP response's top-level `message` field immediately, without reading the cached file.
+- No breaking change: callers that already supply explicit date bounds see no difference in behavior.
+- The 48-hour threshold is documented as a named constant (`staleLogsWarningThreshold`), making it easy to tune.
+
+#### Negative
+- The staleness heuristic (48 hours) is repo-cadence-agnostic; low-activity repositories may never trigger the warning even when results are genuinely stale, while repos with infrequent runs could trigger false positives.
+- The warning travels through two encoding layers (render → JSON `message` field → guardrail JSON extraction), creating coupling between `renderLogsOutput` and `buildLogsFileResponse` that can silently break if the output schema changes.
+
+#### Neutral
+- Unit tests cover all four guard conditions: explicit start date, explicit end date, empty result set, and recent-data threshold, providing a regression baseline for future threshold changes.
+- The `renderLogsOutputOptions` struct gains two new fields (`startDate`, `endDate`) that are threaded from `DownloadWorkflowLogs`, a minor expansion of the internal API surface.
+
+---
+
+*ADR created by [adr-writer agent]. Review and finalize before changing status from Draft to Accepted.*
diff --git a/pkg/cli/logs_orchestrator.go b/pkg/cli/logs_orchestrator.go
index 4d5d1fc1297..3759bb56395 100644
--- a/pkg/cli/logs_orchestrator.go
+++ b/pkg/cli/logs_orchestrator.go
@@ -41,6 +41,68 @@ func applyMetricsTurnsToRun(run *WorkflowRun, metrics LogMetrics) {
 	}
 }
 
+// staleLogsWarningThreshold is how old the most recent run in a result set may be,
+// when no explicit start_date/end_date was requested, before we warn the caller
+// that the data may not reflect the truly latest workflow runs.
+//
+// When no date range is supplied, pagination walks backwards through time (paging
+// on run creation date) until it has collected the requested count of runs. In a
+// repository with heavy non-agentic or still-in-progress run volume, this walk can
+// silently settle on an old window without any indication to the caller that more
+// recent runs exist. Passing an explicit start_date/end_date bypasses this ambiguity
+// entirely because it bounds the query server-side, so no warning is needed there.
+const staleLogsWarningThreshold = 48 * time.Hour
+
+// humanizeDuration formats a duration as a coarse, human-readable age such as
+// "11 days" or "5 hours", rather than a raw Go duration string like "264h0m0s".
+func humanizeDuration(d time.Duration) string {
+	if days := int(d.Hours()) / 24; days >= 1 {
+		if days == 1 {
+			return "1 day"
+		}
+		return fmt.Sprintf("%d days", days)
+	}
+	if hours := int(d.Hours()); hours >= 1 {
+		if hours == 1 {
+			return "1 hour"
+		}
+		return fmt.Sprintf("%d hours", hours)
+	}
+	return "less than 1 hour"
+}
+
+// staleLogsWarning returns a warning message when a date-unbounded logs query
+// (no start_date/end_date requested) returns a result set whose most recent run
+// is unexpectedly old. Returns "" when no warning is warranted, i.e. when an
+// explicit date range was requested, there are no runs, or the newest run is
+// recent enough.
+func staleLogsWarning(processedRuns []ProcessedRun, startDate, endDate string) string {
+	if startDate != "" || endDate != "" {
+		// Caller supplied an explicit bound; the result is exactly what was asked for.
+		return ""
+	}
+	if len(processedRuns) == 0 {
+		return ""
+	}
+	var newest time.Time
+	for _, pr := range processedRuns {
+		if pr.Run.CreatedAt.After(newest) {
+			newest = pr.Run.CreatedAt
+		}
+	}
+	if newest.IsZero() {
+		return ""
+	}
+	age := time.Since(newest)
+	if age < staleLogsWarningThreshold {
+		return ""
+	}
+	return fmt.Sprintf(
+		"No start_date/end_date was specified, and the most recent run in this result is %s old (created %s). "+
+			"Retry with an explicit start_date (e.g. \"-1d\") to confirm you are seeing the latest workflow runs.",
+		humanizeDuration(age), newest.Format(time.RFC3339))
+}
+
 // noRunsMessage returns a human-readable explanation for why zero workflow runs
 // were returned.  It inspects the startDate filter and the timeoutReached flag
 // so callers receive actionable guidance instead of a silent empty result.
@@ -183,5 +245,8 @@ func DownloadWorkflowLogs(ctx context.Context, opts LogsDownloadOptions) error {
 		continuation:   continuation,
 		verbose:        opts.Verbose,
 		artifactFilter: runtime.artifactFilter,
+		startDate:      opts.StartDate,
+		endDate:        opts.EndDate,
+		checkStaleness: true,
 	})
 }
diff --git a/pkg/cli/logs_orchestrator_render.go b/pkg/cli/logs_orchestrator_render.go
index 040fb8ae663..a169132bed9 100644
--- a/pkg/cli/logs_orchestrator_render.go
+++ b/pkg/cli/logs_orchestrator_render.go
@@ -10,6 +10,7 @@ import (
 	"io"
 	"os"
 	"path/filepath"
+	"strings"
 
 	"github.com/github/gh-aw/pkg/constants"
 )
@@ -29,10 +30,26 @@ func renderLogsOutput(processedRuns []ProcessedRun, opts renderLogsOutputOptions
 	logsOrchestratorLog.Printf("Building logs data from %d processed runs (continuation=%t)", len(processedRuns), opts.continuation != nil)
 	logsData := buildLogsData(processedRuns, opts.outputDir, opts.continuation)
 
+	// When no explicit start_date/end_date was requested and the newest run in the
+	// result is unexpectedly old, warn the caller so stale data is never served
+	// silently (see issue: logs MCP tool returns stale data without date params).
+	// This only applies to discovery-mode rendering (pagination walking backwards
+	// through time); the stdin path processes explicit run IDs with no pagination,
+	// so the check is skipped there.
+	if opts.checkStaleness {
+		if warning := staleLogsWarning(processedRuns, opts.startDate, opts.endDate); warning != "" {
+			logsData.StaleWarning = warning
+		}
+	}
+
 	// When only the usage artifact was downloaded, add a hint so consumers know how
 	// to fetch additional artifact sets (agent logs, firewall data, etc.).
+	var hints []string
 	if isUsageOnlyArtifactFilter(opts.artifactFilter) {
-		logsData.Message = usageOnlyArtifactHintMessage()
+		hints = append(hints, usageOnlyArtifactHintMessage())
+	}
+	if len(hints) > 0 {
+		logsData.Message = strings.Join(hints, " ")
 	}
 
 	// Write summary file if requested (default behavior unless disabled with empty string)
diff --git a/pkg/cli/logs_orchestrator_types.go b/pkg/cli/logs_orchestrator_types.go
index d9568d999ae..af50a03937b 100644
--- a/pkg/cli/logs_orchestrator_types.go
+++ b/pkg/cli/logs_orchestrator_types.go
@@ -89,4 +89,11 @@ type renderLogsOutputOptions struct {
 	continuation   *ContinuationData
 	verbose        bool
 	artifactFilter []string
+	startDate      string
+	endDate        string
+	// checkStaleness enables the stale-data warning check. It is only meaningful
+	// for discovery-mode rendering (pagination walking backwards through time
+	// looking for runs); the stdin path processes explicit run IDs with no
+	// pagination, so it leaves this false.
+	checkStaleness bool
 }
diff --git a/pkg/cli/logs_orchestrator_unit_test.go b/pkg/cli/logs_orchestrator_unit_test.go
index 5f8853f655f..5baa1f39f91 100644
--- a/pkg/cli/logs_orchestrator_unit_test.go
+++ b/pkg/cli/logs_orchestrator_unit_test.go
@@ -368,3 +368,44 @@ func TestCollectProcessedWorkflowRunsAccumulatesBatches(t *testing.T) {
 	assert.Equal(t, int64(1), runs[0].Run.DatabaseID)
 	assert.Equal(t, int64(3), runs[2].Run.DatabaseID)
 }
+
+// TestStaleLogsWarning verifies that a warning is only emitted when no explicit
+// start_date/end_date was requested and the newest run in the result set is older
+// than the staleness threshold. This guards against the "logs" tool silently
+// serving stale data without any indication when called with only a count.
+func TestStaleLogsWarning(t *testing.T) {
+	t.Run("no warning when start date explicitly provided", func(t *testing.T) {
+		runs := []ProcessedRun{{Run: WorkflowRun{CreatedAt: time.Now().Add(-30 * 24 * time.Hour)}}}
+		assert.Empty(t, staleLogsWarning(runs, "-1d", ""))
+	})
+
+	t.Run("no warning when end date explicitly provided", func(t *testing.T) {
+		runs := []ProcessedRun{{Run: WorkflowRun{CreatedAt: time.Now().Add(-30 * 24 * time.Hour)}}}
+		assert.Empty(t, staleLogsWarning(runs, "", "2024-01-01"))
+	})
+
+	t.Run("no warning when no runs", func(t *testing.T) {
+		assert.Empty(t, staleLogsWarning(nil, "", ""))
+	})
+
+	t.Run("no warning when newest run is recent", func(t *testing.T) {
+		runs := []ProcessedRun{
+			{Run: WorkflowRun{CreatedAt: time.Now().Add(-1 * time.Hour)}},
+			{Run: WorkflowRun{CreatedAt: time.Now().Add(-40 * 24 * time.Hour)}},
+		}
+		assert.Empty(t, staleLogsWarning(runs, "", ""))
+	})
+
+	t.Run("warns when no dates given and newest run is old", func(t *testing.T) {
+		newest := time.Now().Add(-11 * 24 * time.Hour)
+		runs := []ProcessedRun{
+			{Run: WorkflowRun{CreatedAt: newest}},
+			{Run: WorkflowRun{CreatedAt: newest.Add(-time.Hour)}},
+		}
+		warning := staleLogsWarning(runs, "", "")
+		require.NotEmpty(t, warning)
+		assert.Contains(t, warning, "No start_date/end_date was specified")
+		assert.Contains(t, warning, "start_date")
+		assert.Contains(t, warning, "11 day")
+	})
+}
diff --git a/pkg/cli/logs_output_hint_test.go b/pkg/cli/logs_output_hint_test.go
index 2eb01e5b1ec..bdf2d598c82 100644
--- a/pkg/cli/logs_output_hint_test.go
+++ b/pkg/cli/logs_output_hint_test.go
@@ -55,3 +55,42 @@ func TestRenderLogsOutputWritesArtifactHintForNonCompactFormats(t *testing.T) {
 		})
 	}
 }
+
+func TestRenderLogsOutputStaleWarningGatedByCheckStaleness(t *testing.T) {
+	// A result set whose newest run is well past the staleness threshold with no
+	// start_date/end_date requested.
+	processedRuns := []ProcessedRun{{
+		Run: WorkflowRun{
+			DatabaseID:   1,
+			Status:       "completed",
+			WorkflowName: "logs",
+			CreatedAt:    time.Now().Add(-11 * 24 * time.Hour),
+		},
+	}}
+
+	t.Run("discovery mode surfaces the stale warning", func(t *testing.T) {
+		stdout, _ := captureOutput(t, func() error {
+			return renderLogsOutput(processedRuns, renderLogsOutputOptions{
+				outputDir:      t.TempDir(),
+				format:         "console",
+				jsonOutput:     true,
+				checkStaleness: true,
+			})
+		})
+
+		assert.Contains(t, stdout, "No start_date/end_date was specified")
+	})
+
+	t.Run("stdin/explicit-run mode does not surface the stale warning", func(t *testing.T) {
+		stdout, _ := captureOutput(t, func() error {
+			return renderLogsOutput(processedRuns, renderLogsOutputOptions{
+				outputDir:  t.TempDir(),
+				format:     "console",
+				jsonOutput: true,
+				// checkStaleness left false, as it is for DownloadWorkflowLogsFromStdin.
+			})
+		})
+
+		assert.NotContains(t, stdout, "No start_date/end_date was specified")
+	})
+}
diff --git a/pkg/cli/logs_report.go b/pkg/cli/logs_report.go
index 1782f569561..cbf1009a553 100644
--- a/pkg/cli/logs_report.go
+++ b/pkg/cli/logs_report.go
@@ -39,6 +39,7 @@ type LogsData struct {
 	Continuation      *ContinuationData          `json:"continuation,omitempty" console:"-"`
 	LogsLocation      string                     `json:"logs_location" console:"-"`
 	Message           string                     `json:"message,omitempty" console:"-"`
+	StaleWarning      string                     `json:"stale_warning,omitempty" console:"-"`
 }
 
 // ContinuationData provides parameters to continue querying when timeout is reached
diff --git a/pkg/cli/mcp_logs_guardrail.go b/pkg/cli/mcp_logs_guardrail.go
index 513bdf7a71b..ba13ddce9c7 100644
--- a/pkg/cli/mcp_logs_guardrail.go
+++ b/pkg/cli/mcp_logs_guardrail.go
@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"strings"
 
 	"github.com/github/gh-aw/pkg/constants"
 	"github.com/github/gh-aw/pkg/logger"
@@ -51,6 +52,23 @@ func extractLogsContinuation(outputStr string) *ContinuationData {
 	return parsed.Continuation
 }
 
+// extractLogsStaleWarning returns the top-level "stale_warning" field embedded
+// in the logs JSON output, or "" when absent or unparseable. This is a
+// dedicated field (distinct from the generic "message" field, which is also
+// used for non-warning hints such as the usage-only artifact hint) so that
+// only genuine stale-data warnings are surfaced as "WARNING" in the MCP
+// response.
+func extractLogsStaleWarning(outputStr string) string {
+	var parsed struct {
+		StaleWarning string `json:"stale_warning"`
+	}
+	if err := json.Unmarshal([]byte(outputStr), &parsed); err != nil {
+		mcpLogsGuardrailLog.Printf("extractLogsStaleWarning: failed to parse output JSON: %v", err)
+		return ""
+	}
+	return parsed.StaleWarning
+}
+
 // buildLogsFileResponse writes the logs JSON output to a content-addressed cache
 // file and returns a JSON response containing the file path.
 // The file is named by the SHA256 hash of its content so that identical results
@@ -134,14 +152,25 @@ func buildLogsFileResponse(outputStr string) string {
 	}
 
 	response := MCPLogsGuardrailResponse{
-		Message:  fmt.Sprintf("Logs data has been written to '%s'. Use the file_path to read the full data.", filePath),
 		FilePath: filePath,
 	}
-	if continuation := extractLogsContinuation(outputStr); continuation != nil {
+
+	var msgs []string
+	continuation := extractLogsContinuation(outputStr)
+	if continuation != nil {
 		response.Partial = true
 		response.Continuation = continuation
-		response.Message = fmt.Sprintf("PARTIAL RESULTS: the download stopped before all matching runs were collected. %s Partial logs data has been written to '%s'. Use the file_path to read the collected data and the continuation parameters to fetch the remaining logs.", continuation.Message, filePath)
+		msgs = append(msgs, fmt.Sprintf("PARTIAL RESULTS: the download stopped before all matching runs were collected. %s Partial logs data has been written to '%s'. Use the file_path to read the collected data and the continuation parameters to fetch the remaining logs.", continuation.Message, filePath))
+	} else {
+		msgs = append(msgs, fmt.Sprintf("Logs data has been written to '%s'. Use the file_path to read the full data.", filePath))
+	}
+	// Surface the stale-data warning (when no date range was requested and the
+	// newest run returned is unexpectedly old) directly in the tool response so
+	// callers see it without having to open the file.
+	if warning := extractLogsStaleWarning(outputStr); warning != "" {
+		msgs = append(msgs, "WARNING: "+warning)
 	}
+	response.Message = strings.Join(msgs, " ")
 
 	responseJSON, err := json.MarshalIndent(response, "", "  ")
 	if err != nil {
diff --git a/pkg/cli/mcp_logs_guardrail_test.go b/pkg/cli/mcp_logs_guardrail_test.go
index 146d7d08cdc..074c02c0585 100644
--- a/pkg/cli/mcp_logs_guardrail_test.go
+++ b/pkg/cli/mcp_logs_guardrail_test.go
@@ -207,3 +207,45 @@ func TestBuildLogsFileResponse_CompleteResultsNotPartial(t *testing.T) {
 	// Cleanup
 	_ = os.Remove(response.FilePath)
 }
+
+func TestBuildLogsFileResponse_SurfacesStaleDataWarning(t *testing.T) {
+	output := `{"summary":{"total_runs":1},"runs":[],"stale_warning":"No start_date/end_date was specified, and the most recent run in this result is 11 days old."}`
+
+	result := buildLogsFileResponse(output)
+
+	var response MCPLogsGuardrailResponse
+	if err := json.Unmarshal([]byte(result), &response); err != nil {
+		t.Fatalf("Response should be valid JSON: %v", err)
+	}
+
+	if !strings.Contains(response.Message, "WARNING:") {
+		t.Errorf("Message should surface the embedded warning, got %q", response.Message)
+	}
+	if !strings.Contains(response.Message, "No start_date/end_date was specified") {
+		t.Errorf("Message should include the stale-data warning text, got %q", response.Message)
+	}
+
+	// Cleanup
+	_ = os.Remove(response.FilePath)
+}
+
+func TestBuildLogsFileResponse_DoesNotWarnOnOrdinaryMessage(t *testing.T) {
+	// A non-stale "message" field (e.g. the usage-only artifact hint) must not
+	// be relabeled as a WARNING; only the dedicated "stale_warning" field should
+	// trigger the WARNING prefix.
+	output := `{"summary":{"total_runs":1},"runs":[],"message":"Only the usage artifact was downloaded."}`
+
+	result := buildLogsFileResponse(output)
+
+	var response MCPLogsGuardrailResponse
+	if err := json.Unmarshal([]byte(result), &response); err != nil {
+		t.Fatalf("Response should be valid JSON: %v", err)
+	}
+
+	if strings.Contains(response.Message, "WARNING:") {
+		t.Errorf("Message should not contain WARNING for a non-stale message, got %q", response.Message)
+	}
+
+	// Cleanup
+	_ = os.Remove(response.FilePath)
+}