Added value: +{
+  "description": "When the catalogue that answered was loaded (ISO 8601). Present only when a refresh failed and that older copy is still in service; omitted otherwise.",
+  "type": "string"
+}

Added value: +{
+  "description": "True on a browse of ext_go or icts when the Comext dataflow list could not be loaded, so the DS-* collection folder filed there is not listed. Omitted otherwise.",
+  "type": "boolean"
+}

Previous value: -"Machine-readable failure mode. Declared by this tool: `not_found`: The provided theme_code does not exist in the TOC. `not_a_folder`: The provided theme_code identifies a dataset or table entry instead of a folder. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `not_found`: The provided theme_code does not exist in the TOC — or is a Comext folder (ext_go_detail, prom, comext) or DS-* code while the Comext dataflow list cannot be loaded. `not_a_folder`: The provided theme_code identifies a dataset or table entry instead of a folder. `upstream_fault`: The server had no catalogue loaded yet, and Eurostat's table of contents answered HTTP 5xx or could not be reached on every retry, which the error marks retryable. Once a catalogue is loaded, a failed refresh serves that copy instead. Other values are possible when a failure originates below the handler."

Previous value: -[
-  "not_found",
-  "not_a_folder"
-]New value: +[
+  "not_found",
+  "not_a_folder",
+  "upstream_fault"
+]

Added value: +{
+  "description": "Names each part of the catalogue this listing is missing — the Comext collections, or updates since a refresh failed — and what to do about it. Omitted when the whole catalogue answered.",
+  "type": "string"
+}

Previous value: -"Machine-readable failure mode. Declared by this tool: `not_found`: The provided theme_code does not exist as a folder in the TOC. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `not_found`: The provided theme_code does not exist in the TOC. `not_a_folder`: The provided theme_code identifies a dataset or table entry instead of a folder. Other values are possible when a failure originates below the handler."

Previous value: -[
-  "not_found"
-]New value: +[
+  "not_found",
+  "not_a_folder"
+]

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +false

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

Added value: +[
+  {
+    "not": {
+      "required": [
+        "error"
+      ]
+    },
+    "required": [
+      "items",
+      "parentPath",
+      "itemCount"
+    ]
+  },
+  {
+    "required": [
+      "error"
+    ]
+  }
+]

Added value: +{
+  "additionalProperties": {},
+  "description": "Present when the call failed. Absent on success.",
+  "properties": {
+    "code": {
+      "description": "JSON-RPC error code for this failure.",
+      "maximum": 9007199254740991,
+      "minimum": -9007199254740991,
+      "type": "integer"
+    },
+    "data": {
+      "additionalProperties": {},
+      "properties": {
+        "reason": {
+          "description": "Machine-readable failure mode. Declared by this tool: `not_found`: The provided theme_code does not exist as a folder in the TOC. Other values are possible when a failure originates below the handler.",
+          "examples": [
+            "not_found"
+          ],
+          "type": "string"
+        },
+        "recovery": {
+          "additionalProperties": {},
+          "description": "Actionable next step for the caller.",
+          "properties": {
+            "hint": {
+              "type": "string"
+            }
+          },
+          "required": [
+            "hint"
+          ],
+          "type": "object"
+        },
+        "retryable": {
+          "description": "Whether retrying may succeed.",
+          "type": "boolean"
+        }
+      },
+      "type": "object"
+    },
+    "message": {
+      "description": "Human-readable description of what went wrong.",
+      "type": "string"
+    }
+  },
+  "required": [
+    "code",
+    "message"
+  ],
+  "type": "object"
+}

Removed value: -[
-  "items",
-  "parentPath",
-  "itemCount"
-]

Added value: +{
+  "description": "Breadcrumbs of the other branches that file this same theme_code. Eurostat lists a few folder codes in more than one branch; the items above come from the first one the catalogue lists, which never has fewer children than the branches named here but can list different ones. theme_code takes a bare code, so those branches cannot be addressed directly — browse down to them from the root instead. Omitted when the code has a single placement — the normal case.",
+  "items": {
+    "description": "Breadcrumb from root to one other folder carrying the requested code.",
+    "items": {
+      "type": "string"
+    },
+    "type": "array"
+  },
+  "type": "array"
+}

Previous value: -"Folder code to expand (e.g., \"econ\", \"reg\"). Omit to list the top-level theme folders."New value: +"Folder code to expand (e.g., \"economy\", \"reg\"). Omit to list the top-level theme folders."

Previous value: -"Breadcrumb from root to the requested theme (e.g., [\"Economy and finance\", \"National accounts\"]). Empty when browsing root."New value: +"Breadcrumb from root to the requested theme (e.g., [\"Database by themes\", \"Economy and finance\"]). Empty when browsing root."

Previous value: -"Folder code to expand (e.g., \"econ\", \"reg\"). Omit to list the 11 top-level theme folders."New value: +"Folder code to expand (e.g., \"econ\", \"reg\"). Omit to list the top-level theme folders."

Previous value: -"Immediate children of the requested theme, or the 11 root themes if theme_code was omitted."New value: +"Immediate children of the requested theme, or the root themes if theme_code was omitted."

Added value: +{
+  "description": "Suggested next action based on these results. Populated when there is a clear follow-up call.",
+  "type": "string"
+}

Added value: +{
+  "description": "Number of items returned in this level.",
+  "type": "number"
+}

Added value: +{
+  "description": "Folder code that was browsed, or omitted for root.",
+  "type": "string"
+}

Previous value: -[
-  "items",
-  "parentPath"
-]New value: +[
+  "items",
+  "parentPath",
+  "itemCount"
+]