diff --git a/aws/disk.go b/aws/disk.go
index 77da98e..51f0d27 100644
--- a/aws/disk.go
+++ b/aws/disk.go
@@ -9,16 +9,25 @@ import (
 
 var _ unused.Disk = &Disk{}
 
+// Disk holds information about an AWS EC2 volume.
 type Disk struct {
 	types.Volume
 	provider *Provider
 	meta     unused.Meta
 }
 
+// ID returns the volume ID of this AWS EC2 volume.
 func (d *Disk) ID() string { return *d.Volume.VolumeId }
 
+// Provider returns a reference to the provider used to instantiate
+// this disk.
 func (d *Disk) Provider() unused.Provider { return d.provider }
 
+// Name returns the name of this AWS EC2 volume.
+//
+// AWS EC2 volumes do not have a name property, instead they store the
+// name in tags. This method will try to find the Name or
+// CSIVolumeName, otherwise it will return empty.
 func (d *Disk) Name() string {
 	for _, t := range d.Volume.Tags {
 		if *t.Key == "Name" || *t.Key == "CSIVolumeName" {
@@ -28,8 +37,12 @@ func (d *Disk) Name() string {
 	return ""
 }
 
+// CreatedAt returns the time when the AWS EC2 volume was created.
 func (d *Disk) CreatedAt() time.Time { return *d.Volume.CreateTime }
 
+// Meta returns the disk metadata.
 func (d *Disk) Meta() unused.Meta { return d.meta }
 
+// LastUsedAt returns a zero [time.Time] value, as AWS does not
+// provide this information.
 func (d *Disk) LastUsedAt() time.Time { return time.Time{} }
diff --git a/aws/provider.go b/aws/provider.go
index a6f8cce..e1649ec 100644
--- a/aws/provider.go
+++ b/aws/provider.go
@@ -12,15 +12,23 @@ import (
 
 var _ unused.Provider = &Provider{}
 
+// Provider implements [unused.Provider] for AWS.
 type Provider struct {
 	client *ec2.Client
 	meta   unused.Meta
 }
 
+// Name returns AWS.
 func (p *Provider) Name() string { return "AWS" }
 
+// Meta returns the provider metadata.
 func (p *Provider) Meta() unused.Meta { return p.meta }
 
+// NewProvider creates a new AWS [unused.Provider].
+//
+// A valid EC2 client must be supplied in order to list the unused
+// resources. The metadata passed will be used to identify the
+// provider.
 func NewProvider(client *ec2.Client, meta unused.Meta) (*Provider, error) {
 	if meta == nil {
 		meta = make(unused.Meta)
@@ -32,6 +40,8 @@ func NewProvider(client *ec2.Client, meta unused.Meta) (*Provider, error) {
 	}, nil
 }
 
+// ListUnusedDisks returns all the AWS EC2 volumes that are available,
+// ie. not used by any other resource.
 func (p *Provider) ListUnusedDisks(ctx context.Context) (unused.Disks, error) {
 	params := &ec2.DescribeVolumesInput{
 		Filters: []types.Filter{
@@ -72,6 +82,7 @@ func (p *Provider) ListUnusedDisks(ctx context.Context) (unused.Disks, error) {
 	return upds, nil
 }
 
+// Delete deletes the given disk from AWS.
 func (p *Provider) Delete(ctx context.Context, disk unused.Disk) error {
 	_, err := p.client.DeleteVolume(ctx, &ec2.DeleteVolumeInput{
 		VolumeId: aws.String(disk.ID()),
diff --git a/azure/disk.go b/azure/disk.go
index 44ed5f1..2aa53c5 100644
--- a/azure/disk.go
+++ b/azure/disk.go
@@ -9,20 +9,30 @@ import (
 
 var _ unused.Disk = &Disk{}
 
+// Disk holds information about an Azure compute disk.
 type Disk struct {
 	compute.Disk
 	provider *Provider
 	meta     unused.Meta
 }
 
+// ID returns the Azure compute disk ID.
 func (d *Disk) ID() string { return *d.Disk.ID }
 
+// Provider returns a reference to the provider used to instantiate
+// this disk.
 func (d *Disk) Provider() unused.Provider { return d.provider }
 
+// Name returns the name of this Azure compute disk.
 func (d *Disk) Name() string { return *d.Disk.Name }
 
+// CreatedAt returns the time when this Azure compute disk was
+// created.
 func (d *Disk) CreatedAt() time.Time { return d.Disk.TimeCreated.ToTime() }
 
+// Meta returns the disk metadata.
 func (d *Disk) Meta() unused.Meta { return d.meta }
 
+// LastUsedAt returns a zero [time.Time] value, as Azure does not
+// provide this information.
 func (d *Disk) LastUsedAt() time.Time { return time.Time{} }
diff --git a/azure/provider.go b/azure/provider.go
index 7736444..f3d85b0 100644
--- a/azure/provider.go
+++ b/azure/provider.go
@@ -13,15 +13,22 @@ var _ unused.Provider = &Provider{}
 
 const ResourceGroupMetaKey = "resource-group"
 
+// Providcer implements [unused.Provider] for Azure.
 type Provider struct {
 	client compute.DisksClient
 	meta   unused.Meta
 }
 
+// Name returns Azure.
 func (p *Provider) Name() string { return "Azure" }
 
+// Meta returns the provider metadata.
 func (p *Provider) Meta() unused.Meta { return p.meta }
 
+// NewProvider creates a new Azure [unused.Provider].
+//
+// A valid Azure compute disks client must be supplied in order to
+// list the unused resources.
 func NewProvider(client compute.DisksClient, meta unused.Meta) (*Provider, error) {
 	if meta == nil {
 		meta = make(unused.Meta)
@@ -30,6 +37,8 @@ func NewProvider(client compute.DisksClient, meta unused.Meta) (*Provider, error
 	return &Provider{client: client, meta: meta}, nil
 }
 
+// ListUnusedDisks returns all the Azure compute disks that are not
+// managed by other resources.
 func (p *Provider) ListUnusedDisks(ctx context.Context) (unused.Disks, error) {
 	var upds unused.Disks
 
@@ -69,6 +78,7 @@ func (p *Provider) ListUnusedDisks(ctx context.Context) (unused.Disks, error) {
 	return upds, nil
 }
 
+// Delete deletes the given disk from Azure.
 func (p *Provider) Delete(ctx context.Context, disk unused.Disk) error {
 	_, err := p.client.Delete(ctx, disk.Meta()[ResourceGroupMetaKey], disk.Name())
 	if err != nil {
diff --git a/gcp/disk.go b/gcp/disk.go
index 8c3694f..6be8bf8 100644
--- a/gcp/disk.go
+++ b/gcp/disk.go
@@ -11,18 +11,24 @@ import (
 // ensure we are properly defining the interface
 var _ unused.Disk = &Disk{}
 
+// Disk holds information about a GCP compute disk.
 type Disk struct {
 	*compute.Disk
 	provider *Provider
 	meta     unused.Meta
 }
 
-func (d *Disk) ID() string { return fmt.Sprintf("gcp-disk-%d", d.Disk.Id) }
+// ID returns the GCP compute disk ID, prefixed by gcp-disk.
+func (d *Disk) ID() string { return fmt.Sprintf("gcp-disk-%d", d.Disk.Id) } // TODO remove prefix
 
+// Provider returns a reference to the provider used to instantiate
+// this disk.
 func (d *Disk) Provider() unused.Provider { return d.provider }
 
+// Name returns the name of the GCP compute disk.
 func (d *Disk) Name() string { return d.Disk.Name }
 
+// CreatedAt returns the time when the GCP compute disk was created.
 func (d *Disk) CreatedAt() time.Time {
 	// it's safe to assume GCP will send a valid timestamp
 	c, _ := time.Parse(time.RFC3339, d.Disk.CreationTimestamp)
@@ -30,8 +36,11 @@ func (d *Disk) CreatedAt() time.Time {
 	return c
 }
 
+// Meta returns the disk metadata.
 func (d *Disk) Meta() unused.Meta { return d.meta }
 
+// LastUsedAt returns the time when the GCP compute disk was last
+// detached.
 func (d *Disk) LastUsedAt() time.Time {
 	// it's safe to assume GCP will send a valid timestamp
 	t, _ := time.Parse(time.RFC3339, d.Disk.LastDetachTimestamp)
diff --git a/gcp/provider.go b/gcp/provider.go
index 706a66f..be69eea 100644
--- a/gcp/provider.go
+++ b/gcp/provider.go
@@ -11,20 +11,30 @@ import (
 	"google.golang.org/api/compute/v1"
 )
 
+// ErrMissingProject is the error used when no project ID is provided
+// when trying to create a provider.
 var ErrMissingProject = errors.New("missing project id")
 
 var _ unused.Provider = &Provider{}
 
+// Provider implements [unused.Provider] for GCP.
 type Provider struct {
 	project string
 	svc     *compute.Service
 	meta    unused.Meta
 }
 
+// Name returns GCP.
 func (p *Provider) Name() string { return "GCP" }
 
+// Meta returns the provider metadata.
 func (p *Provider) Meta() unused.Meta { return p.meta }
 
+// NewProvider creates a new GCP [unused.Provider].
+//
+// A valid GCP compute service must be supplied in order to listed the
+// unused resources. It also requires a valid project ID which should
+// be the project where the disks were created.
 func NewProvider(svc *compute.Service, project string, meta unused.Meta) (*Provider, error) {
 	if project == "" {
 		return nil, ErrMissingProject
@@ -41,6 +51,8 @@ func NewProvider(svc *compute.Service, project string, meta unused.Meta) (*Provi
 	}, nil
 }
 
+// ListUnusedDisks returns all the GCP compute disks that aren't
+// associated to any users, meaning that are not being in use.
 func (p *Provider) ListUnusedDisks(ctx context.Context) (unused.Disks, error) {
 	var disks unused.Disks
 
@@ -85,6 +97,7 @@ func diskMetadata(d *compute.Disk) (unused.Meta, error) {
 	return m, nil
 }
 
+// Delete deletes the given disk from GCP.
 func (p *Provider) Delete(ctx context.Context, disk unused.Disk) error {
 	_, err := p.svc.Disks.Delete(p.project, disk.Meta()["zone"], disk.Name()).Do()
 	if err != nil {