diff --git a/stackit/internal/services/telemetrylink/link/resource.go b/stackit/internal/services/telemetrylink/link/resource.go
index 9a30a4c25..9052fa1d9 100644
--- a/stackit/internal/services/telemetrylink/link/resource.go
+++ b/stackit/internal/services/telemetrylink/link/resource.go
@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"regexp"
 	"strings"
 	"time"
 
@@ -179,10 +180,24 @@ func (r *telemetryLinkResource) Schema(_ context.Context, _ resource.SchemaReque
 			"display_name": schema.StringAttribute{
 				Description: schemaDescriptions["display_name"],
 				Required:    true,
+				Validators: []validator.String{
+					stringvalidator.LengthBetween(1, 32),
+					stringvalidator.RegexMatches(
+						regexp.MustCompile(`^[a-zA-Z0-9][a-zA-Z0-9 \-]*$`),
+						"The display name must start with an alphanumeric character and can only contain letters, numbers, spaces, and hyphens.",
+					),
+				},
 			},
 			"description": schema.StringAttribute{
 				Description: schemaDescriptions["description"],
 				Optional:    true,
+				Validators: []validator.String{
+					stringvalidator.LengthAtMost(1024),
+					stringvalidator.RegexMatches(
+						regexp.MustCompile(`^([a-zA-Z0-9][a-zA-Z0-9 \-]*)?$`),
+						"The description must start with an alphanumeric character and can only contain letters, numbers, spaces, and hyphens.",
+					),
+				},
 			},
 			"region": schema.StringAttribute{
 				Description: schemaDescriptions["region"],
diff --git a/stackit/internal/services/telemetryrouter/accesstoken/resource.go b/stackit/internal/services/telemetryrouter/accesstoken/resource.go
index a4659171f..5021a8acc 100644
--- a/stackit/internal/services/telemetryrouter/accesstoken/resource.go
+++ b/stackit/internal/services/telemetryrouter/accesstoken/resource.go
@@ -5,9 +5,11 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"regexp"
 	"strings"
 	"time"
 
+	"github.com/hashicorp/terraform-plugin-framework-validators/stringvalidator"
 	"github.com/hashicorp/terraform-plugin-framework/diag"
 	"github.com/hashicorp/terraform-plugin-framework/resource"
 	"github.com/hashicorp/terraform-plugin-framework/resource/schema"
@@ -172,6 +174,13 @@ func (r *telemetryRouterAccessTokenResource) Schema(_ context.Context, _ resourc
 			"display_name": schema.StringAttribute{
 				Description: schemaDescriptions["display_name"],
 				Required:    true,
+				Validators: []validator.String{
+					stringvalidator.LengthBetween(1, 32),
+					stringvalidator.RegexMatches(
+						regexp.MustCompile(`^[a-zA-Z0-9][a-zA-Z0-9 \-]*$`),
+						"The display name must start with an alphanumeric character and can contain only letters, numbers, spaces, and hyphens.",
+					),
+				},
 			},
 			"region": schema.StringAttribute{
 				Description: schemaDescriptions["region"],
@@ -185,6 +194,13 @@ func (r *telemetryRouterAccessTokenResource) Schema(_ context.Context, _ resourc
 			"description": schema.StringAttribute{
 				Description: schemaDescriptions["description"],
 				Optional:    true,
+				Validators: []validator.String{
+					stringvalidator.LengthAtMost(1024),
+					stringvalidator.RegexMatches(
+						regexp.MustCompile(`^([a-zA-Z0-9][a-zA-Z0-9 \-]*)?$`),
+						"The description must start with an alphanumeric character and can only contain letters, numbers, spaces, and hyphens.",
+					),
+				},
 			},
 			"ttl": schema.Int32Attribute{
 				Description: schemaDescriptions["ttl"],
diff --git a/stackit/internal/services/telemetryrouter/destination/resource.go b/stackit/internal/services/telemetryrouter/destination/resource.go
index b4ecb3de3..638f4b064 100644
--- a/stackit/internal/services/telemetryrouter/destination/resource.go
+++ b/stackit/internal/services/telemetryrouter/destination/resource.go
@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"regexp"
 	"strings"
 	"time"
 
@@ -293,6 +294,13 @@ func (r *telemetryRouterDestinationResource) Schema(_ context.Context, _ resourc
 			"display_name": schema.StringAttribute{
 				Description: schemaDescriptions["display_name"],
 				Required:    true,
+				Validators: []validator.String{
+					stringvalidator.LengthBetween(1, 32),
+					stringvalidator.RegexMatches(
+						regexp.MustCompile(`^[a-zA-Z0-9][a-zA-Z0-9 \-]*$`),
+						"The display name must start with an alphanumeric character and can contain only letters, numbers, spaces, and hyphens.",
+					),
+				},
 			},
 			"config": schema.SingleNestedAttribute{
 				Description: schemaDescriptions["config"],
@@ -420,6 +428,13 @@ func (r *telemetryRouterDestinationResource) Schema(_ context.Context, _ resourc
 			"description": schema.StringAttribute{
 				Description: schemaDescriptions["description"],
 				Optional:    true,
+				Validators: []validator.String{
+					stringvalidator.LengthAtMost(1024),
+					stringvalidator.RegexMatches(
+						regexp.MustCompile(`^([a-zA-Z0-9][a-zA-Z0-9 \-]*)?$`),
+						"The description must start with an alphanumeric character and can only contain letters, numbers, spaces, and hyphens.",
+					),
+				},
 			},
 			"creation_time": schema.StringAttribute{
 				Description: schemaDescriptions["creation_time"],
diff --git a/stackit/internal/services/telemetryrouter/instance/resource.go b/stackit/internal/services/telemetryrouter/instance/resource.go
index 8fdcf1134..bc58e371d 100644
--- a/stackit/internal/services/telemetryrouter/instance/resource.go
+++ b/stackit/internal/services/telemetryrouter/instance/resource.go
@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"regexp"
 	"strings"
 	"time"
 
@@ -195,6 +196,13 @@ func (r *telemetryRouterInstanceResource) Schema(_ context.Context, _ resource.S
 			"display_name": schema.StringAttribute{
 				Description: schemaDescriptions["display_name"],
 				Required:    true,
+				Validators: []validator.String{
+					stringvalidator.LengthBetween(1, 32),
+					stringvalidator.RegexMatches(
+						regexp.MustCompile(`^[a-zA-Z0-9][a-zA-Z0-9 \-]*$`),
+						"The display name must start with an alphanumeric character and can contain only letters, numbers, spaces, and hyphens.",
+					),
+				},
 			},
 			"region": schema.StringAttribute{
 				Description: schemaDescriptions["region"],
@@ -208,6 +216,13 @@ func (r *telemetryRouterInstanceResource) Schema(_ context.Context, _ resource.S
 			"description": schema.StringAttribute{
 				Description: schemaDescriptions["description"],
 				Optional:    true,
+				Validators: []validator.String{
+					stringvalidator.LengthAtMost(1024),
+					stringvalidator.RegexMatches(
+						regexp.MustCompile(`^([a-zA-Z0-9][a-zA-Z0-9 \-]*)?$`),
+						"The description must start with an alphanumeric character and can only contain letters, numbers, spaces, and hyphens.",
+					),
+				},
 			},
 			"filter": schema.SingleNestedAttribute{
 				Description: schemaDescriptions["filter"],