Added value: +{
+  "description": "Any selected source copyright status: \"true\" copyrighted, \"false\" public domain in the USA, \"null\" unknown. Empty means all statuses; this is not worldwide legal clearance.",
+  "items": {
+    "enum": [
+      "true",
+      "false",
+      "null"
+    ],
+    "type": "string"
+  },
+  "type": "array"
+}

Added value: +{
+  "description": "Literal prefix of a format MIME key, such as \"text/plain\" or \"text/html\". Blank means unset.",
+  "type": "string"
+}

Previous value: -[
-  {
-    "not": {
-      "required": [
-        "error"
-      ]
-    },
-    "required": [
-      "requestedLimit",
-      "appliedLimit",
-      "books",
-      "totalInCatalog",
-      "truncated",
-      "shown",
-      "cap"
-    ]
-  },
-  {
-    "required": [
-      "error"
-    ]
-  }
-]New value: +[
+  {
+    "not": {
+      "required": [
+        "error"
+      ]
+    },
+    "required": [
+      "requestedLimit",
+      "appliedLimit",
+      "books",
+      "totalInCatalog",
+      "effectiveCriteria",
+      "truncated",
+      "shown",
+      "cap"
+    ]
+  },
+  {
+    "required": [
+      "error"
+    ]
+  }
+]

Added value: +{
+  "additionalProperties": false,
+  "description": "Present only when more matching books exist.",
+  "properties": {
+    "arguments": {
+      "additionalProperties": false,
+      "description": "Executable search arguments preserving all filters. Page 1 may repeat already shown books when the browse cap cuts a page.",
+      "properties": {
+        "author_year_end": {
+          "description": "At least one author has a birth or death year on or before this year (CE positive, BCE negative).",
+          "maximum": 9007199254740991,
+          "minimum": -9007199254740991,
+          "type": "integer"
+        },
+        "author_year_start": {
+          "description": "At least one author has a birth or death year on or after this year (CE positive, BCE negative).",
+          "maximum": 9007199254740991,
+          "minimum": -9007199254740991,
+          "type": "integer"
+        },
+        "copyright": {
+          "description": "Any selected source copyright status: \"true\" copyrighted, \"false\" public domain in the USA, \"null\" unknown. Empty means all statuses; this is not worldwide legal clearance.",
+          "items": {
+            "enum": [
+              "true",
+              "false",
+              "null"
+            ],
+            "type": "string"
+          },
+          "type": "array"
+        },
+        "ids": {
+          "description": "Restrict to these Gutenberg IDs, intersected with other filters. An empty list selects nothing; omit for unrestricted IDs.",
+          "items": {
+            "exclusiveMinimum": 0,
+            "maximum": 9007199254740991,
+            "type": "integer"
+          },
+          "type": "array"
+        },
+        "languages": {
+          "description": "Any listed two-character ISO 639-1 language code; empty means all languages.",
+          "items": {
+            "maxLength": 2,
+            "minLength": 2,
+            "type": "string"
+          },
+          "type": "array"
+        },
+        "mime_type": {
+          "description": "Literal prefix of a format MIME key, such as \"text/plain\" or \"text/html\". Blank means unset.",
+          "type": "string"
+        },
+        "page": {
+          "default": 1,
+          "description": "One-indexed page of at most 32 matches. Pages beyond the result range are errors.",
+          "exclusiveMinimum": 0,
+          "maximum": 9007199254740991,
+          "type": "integer"
+        },
+        "query": {
+          "description": "Every nonblank word must occur in the title or an author name, case-insensitively, as a literal substring. More than four words require the local mirror; live fallback rejects longer queries. Whitespace separates words.",
+          "type": "string"
+        },
+        "sort": {
+          "default": "popular",
+          "description": "Popular orders by source-snapshot downloads in the last 30 days, with ID tie-breaks locally; ascending and descending order by Gutenberg ID.",
+          "enum": [
+            "popular",
+            "ascending",
+            "descending"
+          ],
+          "type": "string"
+        },
+        "topic": {
+          "description": "Case-insensitive phrase in a subject or bookshelf; blank means unset.",
+          "type": "string"
+        }
+      },
+      "required": [
+        "sort",
+        "page"
+      ],
+      "type": "object"
+    },
+    "tool": {
+      "const": "gutenberg_search_books",
+      "description": "Tool to call for the remaining matching books.",
+      "type": "string"
+    }
+  },
+  "required": [
+    "tool",
+    "arguments"
+  ],
+  "type": "object"
+}

Added value: +{
+  "additionalProperties": false,
+  "description": "Normalized browse criteria, including popular sort and first page.",
+  "properties": {
+    "author_year_end": {
+      "description": "At least one author has a birth or death year on or before this year (CE positive, BCE negative).",
+      "maximum": 9007199254740991,
+      "minimum": -9007199254740991,
+      "type": "integer"
+    },
+    "author_year_start": {
+      "description": "At least one author has a birth or death year on or after this year (CE positive, BCE negative).",
+      "maximum": 9007199254740991,
+      "minimum": -9007199254740991,
+      "type": "integer"
+    },
+    "copyright": {
+      "description": "Any selected source copyright status: \"true\" copyrighted, \"false\" public domain in the USA, \"null\" unknown. Empty means all statuses; this is not worldwide legal clearance.",
+      "items": {
+        "enum": [
+          "true",
+          "false",
+          "null"
+        ],
+        "type": "string"
+      },
+      "type": "array"
+    },
+    "ids": {
+      "description": "Restrict to these Gutenberg IDs, intersected with other filters. An empty list selects nothing; omit for unrestricted IDs.",
+      "items": {
+        "exclusiveMinimum": 0,
+        "maximum": 9007199254740991,
+        "type": "integer"
+      },
+      "type": "array"
+    },
+    "languages": {
+      "description": "Any listed two-character ISO 639-1 language code; empty means all languages.",
+      "items": {
+        "maxLength": 2,
+        "minLength": 2,
+        "type": "string"
+      },
+      "type": "array"
+    },
+    "mime_type": {
+      "description": "Literal prefix of a format MIME key, such as \"text/plain\" or \"text/html\". Blank means unset.",
+      "type": "string"
+    },
+    "page": {
+      "default": 1,
+      "description": "One-indexed page of at most 32 matches. Pages beyond the result range are errors.",
+      "exclusiveMinimum": 0,
+      "maximum": 9007199254740991,
+      "type": "integer"
+    },
+    "query": {
+      "description": "Every nonblank word must occur in the title or an author name, case-insensitively, as a literal substring. More than four words require the local mirror; live fallback rejects longer queries. Whitespace separates words.",
+      "type": "string"
+    },
+    "sort": {
+      "default": "popular",
+      "description": "Popular orders by source-snapshot downloads in the last 30 days, with ID tie-breaks locally; ascending and descending order by Gutenberg ID.",
+      "enum": [
+        "popular",
+        "ascending",
+        "descending"
+      ],
+      "type": "string"
+    },
+    "topic": {
+      "description": "Case-insensitive phrase in a subject or bookshelf; blank means unset.",
+      "type": "string"
+    }
+  },
+  "required": [
+    "sort",
+    "page"
+  ],
+  "type": "object"
+}

Previous value: -"Machine-readable failure mode. Declared by this tool: `no_results`: No books match the language/topic filter combination. `catalog_unavailable`: The Project Gutenberg catalog did not answer within the time this server allows for one browse. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `catalog_unavailable`: The Project Gutenberg catalog did not answer within the time this server allows for one browse. Other values are possible when a failure originates below the handler."

Previous value: -[
-  "no_results",
-  "catalog_unavailable"
-]New value: +[
+  "catalog_unavailable"
+]

Added value: +{
+  "description": "Guidance for empty or capped results.",
+  "type": "string"
+}

Previous value: -"Number of books to return (1–32). Default 20 gives a useful overview without overwhelming context."New value: +"Requested number of books. Default 20; requests above 32 are capped locally at 32."

Previous value: -32New value: +9007199254740991

Previous value: -[
-  {
-    "not": {
-      "required": [
-        "error"
-      ]
-    },
-    "required": [
-      "books",
-      "totalInCatalog",
-      "truncated",
-      "shown",
-      "cap"
-    ]
-  },
-  {
-    "required": [
-      "error"
-    ]
-  }
-]New value: +[
+  {
+    "not": {
+      "required": [
+        "error"
+      ]
+    },
+    "required": [
+      "requestedLimit",
+      "appliedLimit",
+      "books",
+      "totalInCatalog",
+      "truncated",
+      "shown",
+      "cap"
+    ]
+  },
+  {
+    "required": [
+      "error"
+    ]
+  }
+]

Added value: +{
+  "description": "Book limit applied locally, at most 32.",
+  "type": "number"
+}

Previous value: -"Top books by download count, most popular first."New value: +"Top books by downloads in the last 30 days at the source snapshot, most popular first."

Previous value: -"Total downloads — the basis for the popularity ranking."New value: +"Downloads in the last 30 days at the source snapshot — the popularity ranking basis."

Previous value: -"True if media_type is \"Text\" AND a UTF-8 text/plain format is available via gutenberg_get_text."New value: +"True for Text records with UTF-8 plain text; HTML-only editions can still have is_readable=true."

Added value: +{
+  "description": "True for non-Sound records with UTF-8 plain text or HTML supported by gutenberg_get_text.",
+  "type": "boolean"
+}

Previous value: -[
-  "id",
-  "title",
-  "authors",
-  "languages",
-  "download_count",
-  "has_plain_text"
-]New value: +[
+  "id",
+  "title",
+  "authors",
+  "languages",
+  "download_count",
+  "has_plain_text",
+  "is_readable"
+]

Added value: +{
+  "description": "Positive integral book limit requested before capping.",
+  "type": "number"
+}

Previous value: -"Download count of the least-popular book shown — omitted books have at most this many downloads."New value: +"Downloads in the last 30 days at the source snapshot for the least-popular book shown; omitted books have at most this count."

Removed value: -[
-  {
-    "type": "number"
-  },
-  {
-    "type": "null"
-  }
-]

Added value: +[
+  "number",
+  "null"
+]

Removed value: -[
-  {
-    "type": "number"
-  },
-  {
-    "type": "null"
-  }
-]

Added value: +[
+  "number",
+  "null"
+]

Previous value: -"Machine-readable failure mode. Declared by this tool: `no_results`: No books match the language/topic filter combination. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `no_results`: No books match the language/topic filter combination. `catalog_unavailable`: The Project Gutenberg catalog did not answer within the time this server allows for one browse. Other values are possible when a failure originates below the handler."

Previous value: -[
-  "no_results"
-]New value: +[
+  "no_results",
+  "catalog_unavailable"
+]

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": [
+      "books",
+      "totalInCatalog",
+      "truncated",
+      "shown",
+      "cap"
+    ]
+  },
+  {
+    "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: `no_results`: No books match the language/topic filter combination. Other values are possible when a failure originates below the handler.",
+          "examples": [
+            "no_results"
+          ],
+          "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: -[
-  "books",
-  "totalInCatalog",
-  "truncated",
-  "shown",
-  "cap"
-]

Previous value: -"True if media_type is \"Text\" AND a text/plain format is available via gutenberg_get_text."New value: +"True if media_type is \"Text\" AND a UTF-8 text/plain format is available via gutenberg_get_text."