diff --git a/prometheus/desc.go b/prometheus/desc.go
index e959162..7b8827f 100644
--- a/prometheus/desc.go
+++ b/prometheus/desc.go
@@ -67,7 +67,7 @@ type Desc struct {
 
 // NewDesc allocates and initializes a new Desc. Errors are recorded in the Desc
 // and will be reported on registration time. variableLabels and constLabels can
-// be nil if no such labels should be set. fqName and help must not be empty.
+// be nil if no such labels should be set. fqName must not be empty.
 //
 // variableLabels only contain the label names. Their label values are variable
 // and therefore not part of the Desc. (They are managed within the Metric.)
@@ -80,10 +80,6 @@ func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *
 		help:           help,
 		variableLabels: variableLabels,
 	}
-	if help == "" {
-		d.err = errors.New("empty help string")
-		return d
-	}
 	if !model.IsValidMetricName(model.LabelValue(fqName)) {
 		d.err = fmt.Errorf("%q is not a valid metric name", fqName)
 		return d
diff --git a/prometheus/examples_test.go b/prometheus/examples_test.go
index 775e03c..538a239 100644
--- a/prometheus/examples_test.go
+++ b/prometheus/examples_test.go
@@ -89,37 +89,6 @@ func ExampleGaugeFunc() {
 	// GaugeFunc 'goroutines_count' registered.
 }
 
-func ExampleCounter() {
-	pushCounter := prometheus.NewCounter(prometheus.CounterOpts{
-		Name: "repository_pushes", // Note: No help string...
-	})
-	err := prometheus.Register(pushCounter) // ... so this will return an error.
-	if err != nil {
-		fmt.Println("Push counter couldn't be registered, no counting will happen:", err)
-		return
-	}
-
-	// Try it once more, this time with a help string.
-	pushCounter = prometheus.NewCounter(prometheus.CounterOpts{
-		Name: "repository_pushes",
-		Help: "Number of pushes to external repository.",
-	})
-	err = prometheus.Register(pushCounter)
-	if err != nil {
-		fmt.Println("Push counter couldn't be registered AGAIN, no counting will happen:", err)
-		return
-	}
-
-	pushComplete := make(chan struct{})
-	// TODO: Start a goroutine that performs repository pushes and reports
-	// each completion via the channel.
-	for range pushComplete {
-		pushCounter.Inc()
-	}
-	// Output:
-	// Push counter couldn't be registered, no counting will happen: descriptor Desc{fqName: "repository_pushes", help: "", constLabels: {}, variableLabels: []} is invalid: empty help string
-}
-
 func ExampleCounterVec() {
 	httpReqs := prometheus.NewCounterVec(
 		prometheus.CounterOpts{
diff --git a/prometheus/histogram.go b/prometheus/histogram.go
index 7086b76..29dc8e3 100644
--- a/prometheus/histogram.go
+++ b/prometheus/histogram.go
@@ -110,8 +110,9 @@ func ExponentialBuckets(start, factor float64, count int) []float64 {
 }
 
 // HistogramOpts bundles the options for creating a Histogram metric. It is
-// mandatory to set Name and Help to a non-empty string. All other fields are
-// optional and can safely be left at their zero value.
+// mandatory to set Name to a non-empty string. All other fields are optional
+// and can safely be left at their zero value, although it is strongly
+// encouraged to set a Help string.
 type HistogramOpts struct {
 	// Namespace, Subsystem, and Name are components of the fully-qualified
 	// name of the Histogram (created by joining these components with
@@ -122,7 +123,7 @@ type HistogramOpts struct {
 	Subsystem string
 	Name      string
 
-	// Help provides information about this Histogram. Mandatory!
+	// Help provides information about this Histogram.
 	//
 	// Metrics with the same fully-qualified name must have the same Help
 	// string.
diff --git a/prometheus/metric.go b/prometheus/metric.go
index ae44621..55e6d86 100644
--- a/prometheus/metric.go
+++ b/prometheus/metric.go
@@ -59,8 +59,9 @@ type Metric interface {
 // implementation XXX has its own XXXOpts type, but in most cases, it is just be
 // an alias of this type (which might change when the requirement arises.)
 //
-// It is mandatory to set Name and Help to a non-empty string. All other fields
-// are optional and can safely be left at their zero value.
+// It is mandatory to set Name to a non-empty string. All other fields are
+// optional and can safely be left at their zero value, although it is strongly
+// encouraged to set a Help string.
 type Opts struct {
 	// Namespace, Subsystem, and Name are components of the fully-qualified
 	// name of the Metric (created by joining these components with
@@ -71,7 +72,7 @@ type Opts struct {
 	Subsystem string
 	Name      string
 
-	// Help provides information about this metric. Mandatory!
+	// Help provides information about this metric.
 	//
 	// Metrics with the same fully-qualified name must have the same Help
 	// string.
diff --git a/prometheus/summary.go b/prometheus/summary.go
index 12ff034..f7e92d8 100644
--- a/prometheus/summary.go
+++ b/prometheus/summary.go
@@ -81,10 +81,10 @@ const (
 )
 
 // SummaryOpts bundles the options for creating a Summary metric. It is
-// mandatory to set Name and Help to a non-empty string. While all other fields
-// are optional and can safely be left at their zero value, it is recommended to
-// explicitly set the Objectives field to the desired value as the default value
-// will change in the upcoming v0.10 of the library.
+// mandatory to set Name to a non-empty string. While all other fields are
+// optional and can safely be left at their zero value, it is recommended to set
+// a help string and to explicitly set the Objectives field to the desired value
+// as the default value will change in the upcoming v0.10 of the library.
 type SummaryOpts struct {
 	// Namespace, Subsystem, and Name are components of the fully-qualified
 	// name of the Summary (created by joining these components with
@@ -95,7 +95,7 @@ type SummaryOpts struct {
 	Subsystem string
 	Name      string
 
-	// Help provides information about this Summary. Mandatory!
+	// Help provides information about this Summary.
 	//
 	// Metrics with the same fully-qualified name must have the same Help
 	// string.