diff --git a/smithy-aws-traits/src/main/java/software/amazon/smithy/aws/traits/clientendpointdiscovery/ClientEndpointDiscoveryValidator.java b/smithy-aws-traits/src/main/java/software/amazon/smithy/aws/traits/clientendpointdiscovery/ClientEndpointDiscoveryValidator.java
index edd0608a531..20fe3fa0d59 100644
--- a/smithy-aws-traits/src/main/java/software/amazon/smithy/aws/traits/clientendpointdiscovery/ClientEndpointDiscoveryValidator.java
+++ b/smithy-aws-traits/src/main/java/software/amazon/smithy/aws/traits/clientendpointdiscovery/ClientEndpointDiscoveryValidator.java
@@ -42,6 +42,9 @@
 @SmithyInternalApi
 public final class ClientEndpointDiscoveryValidator extends AbstractValidator {
     private static final Set<String> VALID_INPUT_MEMBERS = SetUtils.of("Operation", "Identifiers");
+    private static final String MISSING_ERROR_DEFINITION = "MissingErrorDefinition";
+    private static final String UNBOUND_OPERATION = "UnboundOperation";
+    private static final String NO_OPERATIONS = "NoOperations";
 
     @Override
     public List<ValidationEvent> validate(Model model) {
@@ -73,7 +76,8 @@ public List<ValidationEvent> validate(Model model) {
     private List<ValidationEvent> validateTrait(ServiceShape service, ClientEndpointDiscoveryTrait trait) {
         if (!trait.getOptionalError().isPresent()) {
             return ListUtils.of(danger(service, trait,
-                    "Services SHOULD define an error which indicates an endpoint is invalid."));
+                    "Services SHOULD define an error which indicates an endpoint is invalid.",
+                    MISSING_ERROR_DEFINITION));
         }
         return Collections.emptyList();
     }
@@ -86,8 +90,9 @@ private List<ValidationEvent> validateServices(
                 .filter(pair -> !pair.getKey().getAllOperations().contains(pair.getValue().getOperation()))
                 .map(pair -> error(pair.getKey(), String.format(
                         "The operation `%s` must be bound to the service `%s` to use it as the endpoint operation.",
-                        pair.getValue().getOperation(), pair.getKey()
-                )))
+                        pair.getValue().getOperation(), pair.getKey()),
+                        UNBOUND_OPERATION, pair.getValue().getOperation().getName()
+                ))
                 .collect(Collectors.toList());
 
         validationEvents.addAll(endpointDiscoveryServices.keySet().stream()
@@ -96,8 +101,9 @@ private List<ValidationEvent> validateServices(
                         "The service `%s` is configured to use endpoint discovery, but has no operations bound with "
                                 + "the `%s` trait.",
                         service.getId().toString(),
-                        ClientDiscoveredEndpointTrait.ID.toString()
-                )))
+                        ClientDiscoveredEndpointTrait.ID.toString()),
+                        NO_OPERATIONS
+                ))
                 .collect(Collectors.toList()));
         return validationEvents;
     }
diff --git a/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/clientendpointdiscovery/endpoint-error.errors b/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/clientendpointdiscovery/endpoint-error.errors
index be91fa94bda..8dd18d70936 100644
--- a/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/clientendpointdiscovery/endpoint-error.errors
+++ b/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/clientendpointdiscovery/endpoint-error.errors
@@ -1,2 +1,2 @@
-[DANGER] ns.foo#FooService: Services SHOULD define an error which indicates an endpoint is invalid. | ClientEndpointDiscovery
+[DANGER] ns.foo#FooService: Services SHOULD define an error which indicates an endpoint is invalid. | ClientEndpointDiscovery.MissingErrorDefinition
 [ERROR] ns.foo#GetObject: The operation `ns.foo#GetObject` is marked with `aws.api#clientDiscoveredEndpoint` and is bound to the service `ns.foo#BarService` but does not have the required error `ns.foo#InvalidEndpointError`. | ClientEndpointDiscovery
diff --git a/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/clientendpointdiscovery/no-operations.errors b/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/clientendpointdiscovery/no-operations.errors
new file mode 100644
index 00000000000..48966869372
--- /dev/null
+++ b/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/clientendpointdiscovery/no-operations.errors
@@ -0,0 +1 @@
+[WARNING] ns.foo#BazService: The service `ns.foo#BazService` is configured to use endpoint discovery, but has no operations bound with the `aws.api#clientDiscoveredEndpoint` trait. | ClientEndpointDiscovery.NoOperations
diff --git a/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/clientendpointdiscovery/no-operations.smithy b/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/clientendpointdiscovery/no-operations.smithy
new file mode 100644
index 00000000000..ba6dc7936fb
--- /dev/null
+++ b/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/clientendpointdiscovery/no-operations.smithy
@@ -0,0 +1,66 @@
+$version: "2.0"
+
+namespace ns.foo
+
+use aws.api#clientEndpointDiscovery
+use aws.api#clientDiscoveredEndpoint
+
+@clientEndpointDiscovery(
+    operation: DescribeEndpoints,
+    error: InvalidEndpointError,
+)
+service BazService {
+    version: "2021-06-29",
+    operations: [DescribeEndpoints, GetObjectWithEndpointError],
+}
+
+operation DescribeEndpoints {
+    input: DescribeEndpointsInput,
+    output: DescribeEndpointsOutput,
+}
+
+@input
+structure DescribeEndpointsInput {
+    Operation: String,
+    Identifiers: Identifiers,
+}
+
+map Identifiers {
+    key: String,
+    value: String,
+}
+
+@output
+structure DescribeEndpointsOutput {
+    Endpoints: Endpoints,
+}
+
+list Endpoints {
+    member: Endpoint,
+}
+
+structure Endpoint {
+    Address: String,
+    CachePeriodInMinutes: Long,
+}
+
+operation GetObjectWithEndpointError {
+    input: GetObjectWithEndpointErrorInput,
+    output: GetObjectWithEndpointErrorOutput,
+    errors: [InvalidEndpointError],
+}
+
+@input
+structure GetObjectWithEndpointErrorInput {
+    @required
+    Id: String,
+}
+
+@output
+structure GetObjectWithEndpointErrorOutput {
+    Object: Blob,
+}
+
+@error("client")
+@httpError(421)
+structure InvalidEndpointError {}
diff --git a/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/clientendpointdiscovery/unbound-operations.errors b/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/clientendpointdiscovery/unbound-operations.errors
new file mode 100644
index 00000000000..f3954f880cf
--- /dev/null
+++ b/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/clientendpointdiscovery/unbound-operations.errors
@@ -0,0 +1,2 @@
+[ERROR] ns.foo#GetObject: The operation `ns.foo#GetObject` is marked with `aws.api#clientDiscoveredEndpoint` and is bound to the service `ns.foo#BarService` but does not have the required error `ns.foo#InvalidEndpointError`. | ClientEndpointDiscovery
+[ERROR] ns.foo#BarService: The operation `ns.foo#DescribeEndpoints` must be bound to the service `(service: `ns.foo#BarService`)` to use it as the endpoint operation. | ClientEndpointDiscovery.UnboundOperation.DescribeEndpoints
diff --git a/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/clientendpointdiscovery/unbound-operations.smithy b/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/clientendpointdiscovery/unbound-operations.smithy
new file mode 100644
index 00000000000..083ca4fded5
--- /dev/null
+++ b/smithy-aws-traits/src/test/resources/software/amazon/smithy/aws/traits/errorfiles/clientendpointdiscovery/unbound-operations.smithy
@@ -0,0 +1,97 @@
+$version: "2.0"
+
+namespace ns.foo
+
+use aws.api#clientEndpointDiscovery
+use aws.api#clientDiscoveredEndpoint
+
+// This DOES have an error, but it's not bound to the operations. This should
+// result in an ERROR.
+@clientEndpointDiscovery(
+    operation: DescribeEndpoints,
+    error: InvalidEndpointError,
+)
+service BarService {
+    version: "2021-06-29",
+    operations: [GetObject],
+}
+
+// This DOES have an error, and it IS bound to the operations. This should
+// not produce any validation events.
+@clientEndpointDiscovery(
+    operation: DescribeEndpoints,
+    error: InvalidEndpointError,
+)
+service BazService {
+    version: "2021-06-29",
+    operations: [DescribeEndpoints, GetObjectWithEndpointError],
+}
+
+operation DescribeEndpoints {
+    input: DescribeEndpointsInput,
+    output: DescribeEndpointsOutput,
+}
+
+@input
+structure DescribeEndpointsInput {
+    Operation: String,
+    Identifiers: Identifiers,
+}
+
+map Identifiers {
+    key: String,
+    value: String,
+}
+
+@output
+structure DescribeEndpointsOutput {
+    Endpoints: Endpoints,
+}
+
+list Endpoints {
+    member: Endpoint,
+}
+
+structure Endpoint {
+    Address: String,
+    CachePeriodInMinutes: Long,
+}
+
+@clientDiscoveredEndpoint(required: true)
+operation GetObject {
+    input: GetObjectInput,
+    output: GetObjectOutput,
+}
+
+@input
+structure GetObjectInput {
+    @required
+    Id: String,
+}
+
+@output
+structure GetObjectOutput {
+    Object: Blob,
+}
+
+@clientDiscoveredEndpoint(required: true)
+operation GetObjectWithEndpointError {
+    input: GetObjectWithEndpointErrorInput,
+    output: GetObjectWithEndpointErrorOutput,
+    errors: [InvalidEndpointError],
+}
+
+@input
+structure GetObjectWithEndpointErrorInput {
+    @required
+    Id: String,
+}
+
+@output
+structure GetObjectWithEndpointErrorOutput {
+    Object: Blob,
+}
+
+@error("client")
+@httpError(421)
+structure InvalidEndpointError {}