diff --git a/command/agent/metrics_endpoint.go b/command/agent/metrics_endpoint.go
index d8ae838d5..b0702c38a 100644
--- a/command/agent/metrics_endpoint.go
+++ b/command/agent/metrics_endpoint.go
@@ -7,7 +7,8 @@ import (
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
 
-// MetricsRequest returns metrics in JSON format
+// MetricsRequest returns metrics for the agent. Metrics are JSON by default
+// but Prometheus is an optional format.
 func (s *HTTPServer) MetricsRequest(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
 	if req.Method != "GET" {
 		return nil, CodedError(405, ErrInvalidMethod)