diff --git a/docs/openapi.json b/docs/openapi.json
index a078b6d8b..29015eb64 100644
--- a/docs/openapi.json
+++ b/docs/openapi.json
@@ -5363,7 +5363,7 @@
                 ],
                 "summary": "Handle A2A Jsonrpc",
                 "description": "Handle A2A JSON-RPC requests following the A2A protocol specification.\n\nThis endpoint uses the DefaultRequestHandler from the A2A SDK to handle\nall JSON-RPC requests including message/send, message/stream, etc.\n\nThe A2A SDK application is created per-request to include authentication\ncontext while still leveraging FastAPI's authorization middleware.\n\nAutomatically detects streaming requests (message/stream JSON-RPC method)\nand returns a StreamingResponse to enable real-time chunk delivery.\n\nArgs:\n    request: FastAPI request object\n    auth: Authentication tuple\n    mcp_headers: MCP headers for context propagation\n\nReturns:\n    JSON-RPC response or streaming response",
-                "operationId": "handle_a2a_jsonrpc_a2a_post",
+                "operationId": "handle_a2a_jsonrpc_a2a_get",
                 "responses": {
                     "200": {
                         "description": "Successful Response",
@@ -5381,7 +5381,7 @@
                 ],
                 "summary": "Handle A2A Jsonrpc",
                 "description": "Handle A2A JSON-RPC requests following the A2A protocol specification.\n\nThis endpoint uses the DefaultRequestHandler from the A2A SDK to handle\nall JSON-RPC requests including message/send, message/stream, etc.\n\nThe A2A SDK application is created per-request to include authentication\ncontext while still leveraging FastAPI's authorization middleware.\n\nAutomatically detects streaming requests (message/stream JSON-RPC method)\nand returns a StreamingResponse to enable real-time chunk delivery.\n\nArgs:\n    request: FastAPI request object\n    auth: Authentication tuple\n    mcp_headers: MCP headers for context propagation\n\nReturns:\n    JSON-RPC response or streaming response",
-                "operationId": "handle_a2a_jsonrpc_a2a_post",
+                "operationId": "handle_a2a_jsonrpc_a2a_get",
                 "responses": {
                     "200": {
                         "description": "Successful Response",
@@ -8065,7 +8065,7 @@
                     },
                     {
                         "detail": {
-                            "cause": "ClusterVersion missing required field: 'clusterID'",
+                            "cause": "Missing or invalid 'clusterID' in ClusterVersion",
                             "response": "Internal server error"
                         },
                         "label": "invalid cluster version"
diff --git a/src/models/responses.py b/src/models/responses.py
index 20a665060..5c2e974cc 100644
--- a/src/models/responses.py
+++ b/src/models/responses.py
@@ -2449,7 +2449,7 @@ class InternalServerErrorResponse(AbstractErrorResponse):
                     "label": "invalid cluster version",
                     "detail": {
                         "response": "Internal server error",
-                        "cause": "ClusterVersion missing required field: 'clusterID'",
+                        "cause": "Missing or invalid 'clusterID' in ClusterVersion",
                     },
                 },
             ]
diff --git a/tests/unit/authentication/test_k8s.py b/tests/unit/authentication/test_k8s.py
index 89dc4afb0..fe02dbf92 100644
--- a/tests/unit/authentication/test_k8s.py
+++ b/tests/unit/authentication/test_k8s.py
@@ -909,7 +909,7 @@ async def test_kube_admin_invalid_cluster_version_returns_500(
     mocker.patch(
         "authentication.k8s.K8sClientSingleton.get_cluster_id",
         side_effect=InvalidClusterVersionError(
-            "ClusterVersion missing required field: 'clusterID'"
+            "Missing or invalid 'clusterID' in ClusterVersion"
         ),
     )
 
@@ -920,7 +920,7 @@ async def test_kube_admin_invalid_cluster_version_returns_500(
     assert exc_info.value.status_code == 500
     detail = cast(dict[str, str], exc_info.value.detail)
     assert detail["response"] == "Internal server error"
-    assert "ClusterVersion missing required field" in detail["cause"]
+    assert "Missing or invalid 'clusterID' in ClusterVersion" in detail["cause"]
 
 
 @pytest.mark.parametrize(