federal-regulations-mcp-server

Previous value: -"CFR part within the title, in both modes — structure mode lists every section and appendix in the part, flattened and paged by page/per_page; search mode restricts matches to text inside that part. Requires title; a part on its own is rejected. Parts can be alphanumeric (\"1203a\", \"16A\") and are matched exactly, so pass the identifier as eCFR writes it — \"58\", not \"Part 58\" or \"058\"."New value: +"CFR part within the title, in both modes — structure mode lists every section and appendix in the part, flattened and paged by page/per_page; search mode restricts matches to text inside that part. Requires title; a part on its own is rejected. Parts can be alphanumeric (\"1203a\", \"16A\") and are matched exactly once a leading \"Part\" or \"Pt.\" is dropped, so pass the identifier as eCFR writes it — \"58\" (\"Part 58\" also reads as 58), not \"058\"."

Previous value: -"Resolved point-in-time date — the hierarchy snapshot (structure mode), or the day whose section text was searched (search mode, live source only)."New value: +"Resolved point-in-time date — the hierarchy snapshot (structure mode), or the day whose section text was searched (search mode)."

Previous value: -"Assembled cite → regulations_get_cfr_section: \"40 CFR 50.1\" for a section, \"Appendix A-1 to Part 50, Title 40\" for an appendix. Null on a level with no read path (title, subtitle, chapter)."New value: +"Assembled cite → regulations_get_cfr_section: \"40 CFR 50.1\" for a section (\"14 CFR 241 § 25\" for one numbered without its part), \"Appendix A-1 to Part 50, Title 40\" for an appendix. Null on a level with no read path (title, subtitle, chapter)."

Previous value: -"CFR part within the title (e.g. \"50\"). Parts can be alphanumeric. Required unless appendix is given, where it is optional but recommended: an appendix identifier is unique within a part, not within a title, so without a part eCFR picks one of the matches. Obtain from regulations_browse_cfr or a Federal Register document's cfrReferences."New value: +"CFR part within the title (e.g. \"50\"). Parts can be alphanumeric; a leading \"Part\" or \"Pt.\" is dropped (\"Part 141\" reads part 141). Required unless appendix is given, where it is optional but recommended: an appendix identifier is unique within a part, not within a title, so without a part eCFR picks one of the matches. Obtain from regulations_browse_cfr or a Federal Register document's cfrReferences."

Previous value: -"Section within the part, normally written part.section as eCFR identifies it (\"141.61\"). Also accepted: the number alone (\"61\" in part 141), a leading \"§\" or \"Sec.\", and a paragraph cite (\"141.61(c)\"), which reads the whole section. Identifiers eCFR writes differently are read as given — 14 CFR 241 numbers its sections \"25\" and \"1-1\". Omit to fetch the entire part. Cannot be combined with appendix."New value: +"Section within the part, normally written part.section as eCFR identifies it (\"141.61\"). Also accepted: the number alone (\"61\" in part 141), a leading \"§\" or \"Sec.\", a paragraph cite (\"141.61(c)\"), which reads the whole section, and the full cite this tool returns as cfrCite (\"40 CFR 141.61\", \"14 CFR 241 § 25\"), whose title has to match title. Identifiers eCFR writes differently are read as given — 14 CFR 241 numbers its sections \"25\" and \"1-1\". Omit to fetch the entire part. Cannot be combined with appendix."

Added value: +{
+  "description": "The part's Authority — the statutes it is issued under, without the \"Authority:\" label; null when the part states none. Present only on a whole-part read. A subpart or subject group that states its own carries it on its sections[] entries; a single-section or appendix read carries no part- or subpart-level notes, so read the whole part for them.",
+  "type": [
+    "string",
+    "null"
+  ]
+}

Previous value: -"One window of the location's text, starting at bodyTextOffset, XML stripped to plain text. A whole part's text is each section's heading and body in order. Paragraphs, subheadings, editorial notes, tables (one pipe-delimited line per row), figure references (\"[Figure: /graphics/…]\"), and each section's trailing source citation are kept in document order. The source citation is the bracketed Federal Register history a section ends in (\"[36 FR 22384, Nov. 25, 1971, as amended at 81 FR 68276, Oct. 3, 2016]\") — to reach the rulemaking that produced this text, pass one of its cites from 1994 on to regulations_search_rules as citation (\"81 FR 68276\") with the date printed beside it as citation_date (\"2016-10-03\"). Empty when the offset is at or past the end, or where the location is a placeholder carrying nothing but its heading (\"[Reserved]\")."New value: +"One window of the location's text, starting at bodyTextOffset, XML stripped to plain text. A whole part's text is each section's heading and body in order. Paragraphs, subheadings, editorial notes, tables (one pipe-delimited line per row), figure references (\"[Figure: /graphics/…]\"), a section's own statutory authority and OMB control-number note, and its trailing source citation are kept in document order; part-, subpart-, and subject-group-level Authority and Source are not (see authority, sourceNote, and sections[]). Superscripts read ^x and subscripts _x, braced where the run would otherwise be ambiguous (3 × 10^−8, SO_2, CO_{2}e); a footnote reference or label reads [n]; diacritics and overlines are Unicode combining marks on their base character (x̄, R̅M̅). The source citation is the bracketed Federal Register history a section ends in (\"[36 FR 22384, Nov. 25, 1971, as amended at 81 FR 68276, Oct. 3, 2016]\") — to reach the rulemaking that produced this text, pass one of its cites from 1994 on to regulations_search_rules as citation (\"81 FR 68276\") with the date printed beside it as citation_date (\"2016-10-03\"). Empty when the offset is at or past the end, or where the location is a placeholder carrying nothing but its heading (\"[Reserved]\")."

Previous value: -"Machine-readable failure mode. Declared by this tool: `not_found`: No such title/part/section/appendix at that date, under the section as given or any form it resolves to. `location_required`: Neither part nor appendix was given, so the call names no location to read. `conflicting_target`: Both section and appendix were given. They name two different locations, and picking one silently would return text the call did not ask for. `date_out_of_range`: The requested date precedes eCFR historical coverage (2017-01-01) or is past the title's up-to-date date. `upstream_unavailable`: eCFR returned a 5xx, timed out, or served an HTML error page (live path). Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `not_found`: No such title/part/section/appendix at that date, under the section as given or any form it resolves to. `location_required`: Neither part nor appendix was given, so the call names no location to read. `conflicting_target`: Both section and appendix were given. They name two different locations, and picking one silently would return text the call did not ask for. `conflicting_title`: section is written as a full cite (\"21 CFR 141.61\") naming a different title than title. `date_out_of_range`: The requested date precedes eCFR historical coverage (2017-01-01) or is past the title's up-to-date date. `upstream_unavailable`: eCFR returned a 5xx, timed out, or served an HTML error page (live path). Other values are possible when a failure originates below the handler."

Previous value: -[
-  "not_found",
-  "location_required",
-  "conflicting_target",
-  "date_out_of_range",
-  "upstream_unavailable"
-]New value: +[
+  "not_found",
+  "location_required",
+  "conflicting_target",
+  "conflicting_title",
+  "date_out_of_range",
+  "upstream_unavailable"
+]

Previous value: -"Section, part, or appendix heading."New value: +"Section, part, or appendix heading — for a whole part, the part's own (\"PART 141—NATIONAL PRIMARY DRINKING WATER REGULATIONS\")."

Added value: +{
+  "description": "The part's editorial, general, and OMB control-number notes, in document order; empty when it has none. Present only on a whole-part read.",
+  "items": {
+    "description": "One note, its label dropped.",
+    "type": "string"
+  },
+  "type": "array"
+}

Previous value: -"How a section written another way was resolved, and guidance when the offset is at or past the end of the text."New value: +"How a part or section written another way was resolved, and guidance when the offset is at or past the end of the text."

Added value: +{
+  "description": "The Authority its subpart or subject group states for this section; absent when the part's authority applies.",
+  "type": "string"
+}

Added value: +{
+  "description": "The Source note its subpart or subject group states for this section; absent when the part's sourceNote applies.",
+  "type": "string"
+}

Added value: +{
+  "description": "The part's Source note — the Federal Register document it was issued in, without the \"Source:\" label (\"40 FR 59570, Dec. 24, 1975, unless otherwise noted.\"), which holds for every section with no source citation of its own; null when the part states none. Not to be confused with source, which names the corpus that answered. Present only on a whole-part read; subpart and subject-group Source notes ride on sections[] entries.",
+  "type": [
+    "string",
+    "null"
+  ]
+}

Previous value: -"Fetch all comments in a docket by docket ID (e.g. \"EPA-HQ-OAR-2025-0194\"). Broadest scope. Exactly one of docket_id / document_object_id / fr_document_number / comment_id is required — supplying two is rejected, not resolved by precedence."New value: +"Fetch all comments in a docket by Regulations.gov docket ID (e.g. \"EPA-HQ-OAR-2025-0194\") — regulationsGovDocketId on a regulations_search_rules or regulations_list_open_comments row, or docketId from regulations_get_document, not an entry of the printed docketIds. Broadest scope. Exactly one of docket_id / document_object_id / fr_document_number / comment_id is required — supplying two is rejected, not resolved by precedence."

Previous value: -"One window of the location's text, starting at bodyTextOffset, XML stripped to plain text. A whole part's text is each section's heading and body in order. Paragraphs, subheadings, editorial notes, tables (one pipe-delimited line per row), figure references (\"[Figure: /graphics/…]\"), and each section's trailing source citation are kept in document order. The source citation is the bracketed Federal Register history a section ends in (\"[36 FR 22384, Nov. 25, 1971, as amended at 81 FR 68276, Oct. 3, 2016]\") — pass one of its FR cites to regulations_search_rules to reach the rulemaking that produced this text. Empty when the offset is at or past the end, or where the location is a placeholder carrying nothing but its heading (\"[Reserved]\")."New value: +"One window of the location's text, starting at bodyTextOffset, XML stripped to plain text. A whole part's text is each section's heading and body in order. Paragraphs, subheadings, editorial notes, tables (one pipe-delimited line per row), figure references (\"[Figure: /graphics/…]\"), and each section's trailing source citation are kept in document order. The source citation is the bracketed Federal Register history a section ends in (\"[36 FR 22384, Nov. 25, 1971, as amended at 81 FR 68276, Oct. 3, 2016]\") — to reach the rulemaking that produced this text, pass one of its cites from 1994 on to regulations_search_rules as citation (\"81 FR 68276\") with the date printed beside it as citation_date (\"2016-10-03\"). Empty when the offset is at or past the end, or where the location is a placeholder carrying nothing but its heading (\"[Reserved]\")."

Previous value: -"Regulations.gov docket ID (e.g. \"EPA-HQ-OAR-2025-0194\"). Obtain from a Federal Register document's docketId (regulations_get_document) or an agency rulemaking reference."New value: +"Regulations.gov docket ID (e.g. \"EPA-HQ-OAR-2025-0194\"). Obtain from regulationsGovDocketId on a regulations_search_rules or regulations_list_open_comments row, or docketId from regulations_get_document. The printed docketIds on those tools are not always Regulations.gov IDs (\"REG-101355-26\" is the IRS's own number for docket IRS-2026-0925)."

Previous value: -"Comment-period end date; when set, open for comment."New value: +"The UTC instant the comment period ends, or null. Periods end at 11:59 PM Eastern, so \"2023-05-31T03:59:59Z\" is the close date 2023-05-30 the Federal Register prints."

Added value: +{
+  "description": "Whether the document is open for comment now, as Regulations.gov reports it (its openForComment); null when Regulations.gov doesn't say.",
+  "type": [
+    "boolean",
+    "null"
+  ]
+}

Previous value: -[
-  "documentId",
-  "objectId",
-  "title",
-  "documentType",
-  "postedDate",
-  "frDocNum",
-  "commentEndDate",
-  "withdrawn"
-]New value: +[
+  "documentId",
+  "objectId",
+  "title",
+  "documentType",
+  "postedDate",
+  "frDocNum",
+  "commentEndDate",
+  "commentPeriodOpen",
+  "withdrawn"
+]

Previous value: -[
-  {
-    "not": {
-      "required": [
-        "error"
-      ]
-    },
-    "required": [
-      "documentNumber",
-      "title",
-      "type",
-      "abstract",
-      "action",
-      "dates",
-      "publicationDate",
-      "effectiveOn",
-      "commentsCloseOn",
-      "agencies",
-      "regulationIdNumbers",
-      "cfrReferences",
-      "docketId",
-      "regulationsGovDocumentId",
-      "commentCount",
-      "supportingDocuments",
-      "bodyHtmlUrl",
-      "rawTextUrl",
-      "htmlUrl"
-    ]
-  },
-  {
-    "required": [
-      "error"
-    ]
-  }
-]New value: +[
+  {
+    "not": {
+      "required": [
+        "error"
+      ]
+    },
+    "required": [
+      "documentNumber",
+      "title",
+      "type",
+      "abstract",
+      "action",
+      "dates",
+      "publicationDate",
+      "citation",
+      "startPage",
+      "endPage",
+      "effectiveOn",
+      "commentsCloseOn",
+      "commentPeriodOpen",
+      "agencies",
+      "regulationIdNumbers",
+      "cfrReferences",
+      "docketIds",
+      "docketId",
+      "regulationsGovDocumentId",
+      "commentCount",
+      "commentUrl",
+      "supportingDocuments",
+      "bodyHtmlUrl",
+      "rawTextUrl",
+      "htmlUrl"
+    ]
+  },
+  {
+    "required": [
+      "error"
+    ]
+  }
+]

Added value: +{
+  "description": "Where the document starts in the Federal Register (\"89 FR 49101\"); null when none is recorded, as for most of 1994.",
+  "type": [
+    "string",
+    "null"
+  ]
+}

Previous value: -"FR-reported comment count from Regulations.gov; null when not on Regulations.gov."New value: +"Comments Regulations.gov received on this document, as the Federal Register reports it; null when not on Regulations.gov. Can exceed the comment records regulations_find_comments lists."

Added value: +{
+  "description": "Whether that comment period is open today: true through 11:59 PM Eastern on commentsCloseOn, false after it, null when commentsCloseOn is null.",
+  "type": [
+    "boolean",
+    "null"
+  ]
+}

Added value: +{
+  "description": "Regulations.gov page for submitting a comment on this document, as the Federal Register lists it. Null when it lists none, as it usually stops doing once the comment period closes.",
+  "type": [
+    "string",
+    "null"
+  ]
+}

Previous value: -"Comment-period close date (ISO 8601); when set, still open for comment."New value: +"Last day of the comment period this document printed (ISO 8601), inclusive, in Eastern time; null when it prints none. A later extension published as its own document is not reflected here."

Previous value: -"Regulations.gov docket ID — chain into regulations_get_docket / find_comments. Null when not on Regulations.gov."New value: +"Regulations.gov docket ID — chain into regulations_get_docket / regulations_find_comments(docket_id). Null when not on Regulations.gov. An <AGENCY>_FRDOC_0001 docket (EPA_FRDOC_0001 holds 3,451 documents) is Regulations.gov's catch-all for Federal Register documents outside a rulemaking docket, so this document's comments come from regulationsGovDocumentId instead."

Added value: +{
+  "description": "Docket numbers as the Federal Register prints them — an agency's own number (\"REG-101355-26\"), or an ID inside a wrapper (\"Docket No. FAA-2026-8449\"). Pass one to regulations_search_rules as docket_id for every Federal Register document in the docket. Not always a Regulations.gov ID: docketId is.",
+  "items": {
+    "type": "string"
+  },
+  "type": "array"
+}

Added value: +{
+  "description": "Last Federal Register page the document is printed on; null when unrecorded. A CFR source-note cite to any page from startPage to endPage points at this document.",
+  "type": [
+    "number",
+    "null"
+  ]
+}

Added value: +{
+  "description": "First Federal Register page the document is printed on; null when unrecorded.",
+  "type": [
+    "number",
+    "null"
+  ]
+}

Previous value: -"The \"today\" the open-window filter used (ISO 8601)."New value: +"The \"today\" the open window was computed from — the current date in US Eastern time (ISO 8601). A comment period stays open through 11:59 PM Eastern on its close date."

Previous value: -"Whether comment counts were enriched (REGULATIONS_GOV_API_KEY present)."New value: +"Whether REGULATIONS_GOV_API_KEY is set, which decides whether regulations_get_docket and regulations_find_comments can follow up on a row. Every row field is filled either way."

Previous value: -"Guidance when nothing matched, when the page is past the end, when the window was truncated, or that comment counts are unavailable without a key."New value: +"Guidance when nothing matched, when the page is past the end, or when the window was truncated."

Previous value: -"Comment count from the FR document's Regulations.gov info; null when unkeyed or not on Regulations.gov."New value: +"Comments Regulations.gov received on this document, as the Federal Register reports it; null when not on Regulations.gov. Can exceed the comment records regulations_find_comments lists."

Added value: +{
+  "description": "Regulations.gov page for submitting a comment on this document, as the Federal Register lists it; null when it lists none.",
+  "type": [
+    "string",
+    "null"
+  ]
+}

Previous value: -"Comment-period close date (ISO 8601)."New value: +"Last day of the comment period (ISO 8601), inclusive, in Eastern time."

Previous value: -"Whole days from asOf until the comment period closes."New value: +"Whole days from asOf to commentsCloseOn; 0 means comments close at the end of today."

Previous value: -"Docket IDs — chain into regulations_get_docket / find_comments."New value: +"Docket numbers as the Federal Register prints them — an agency's own number (\"REG-101355-26\"), or an ID inside a wrapper (\"Docket No. FAA-2026-8449\"). Pass one to regulations_search_rules as docket_id. Not always a Regulations.gov ID: for regulations_get_docket / regulations_find_comments use regulationsGovDocketId."

Added value: +{
+  "description": "Regulations.gov docket ID — chains into regulations_get_docket / regulations_find_comments(docket_id). Null when the document is not on Regulations.gov. An <AGENCY>_FRDOC_0001 docket (EPA_FRDOC_0001 holds 3,451 documents) is Regulations.gov's catch-all for Federal Register documents outside a rulemaking docket, so this document's comments come from regulationsGovDocumentId instead.",
+  "type": [
+    "string",
+    "null"
+  ]
+}

Added value: +{
+  "description": "Regulations.gov document ID — pass as document_object_id to regulations_find_comments for the comments filed on this document. Null when absent.",
+  "type": [
+    "string",
+    "null"
+  ]
+}

Previous value: -[
-  "documentNumber",
-  "title",
-  "type",
-  "agencies",
-  "publicationDate",
-  "commentsCloseOn",
-  "daysRemaining",
-  "docketIds",
-  "commentCount"
-]New value: +[
+  "documentNumber",
+  "title",
+  "type",
+  "agencies",
+  "publicationDate",
+  "commentsCloseOn",
+  "daysRemaining",
+  "docketIds",
+  "regulationsGovDocketId",
+  "regulationsGovDocumentId",
+  "commentCount",
+  "commentUrl"
+]

Added value: +{
+  "description": "Only documents whose cfrReferences list this part of cfr_title: a part number (\"141\") or a range (\"140-143\"), such as the part regulations_get_cfr_section just read; a \"Part\" or \"pt.\" prefix is dropped. Requires cfr_title. A part with a letter in it (\"1203a\") cannot be filtered on. Unlike a query of \"40 CFR 141\", which matches documents that mention the part, this matches the documents whose CFR references list it.",
+  "type": "string"
+}

Added value: +{
+  "description": "Only documents whose affected CFR parts (cfrReferences) fall in this title (1–50) — such as the title regulations_get_cfr_section just read. Alone it filters to the title; with cfr_part, to that part.",
+  "maximum": 50,
+  "minimum": 1,
+  "type": "integer"
+}

Added value: +{
+  "anyOf": [
+    {
+      "const": "",
+      "type": "string"
+    },
+    {
+      "description": "Federal Register volume and page, \"89 FR 49102\".",
+      "pattern": "^\\s*(\\d{1,3})\\s*[Ff]\\.?\\s?[Rr]\\.?\\s*(\\d{1,6})\\s*$",
+      "type": "string"
+    }
+  ],
+  "description": "A Federal Register page cite, \"89 FR 49102\" (volume FR page) — such as one from the source note that ends a regulations_get_cfr_section bodyText. Returns the documents printed on that page, usually one and sometimes a few sharing it, ordered by start page. Requires citation_date and replaces published_after/published_before. Volume 59 (1994) onward."
+}

Added value: +{
+  "anyOf": [
+    {
+      "const": "",
+      "type": "string"
+    },
+    {
+      "description": "ISO 8601 date (YYYY-MM-DD).",
+      "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
+      "type": "string"
+    }
+  ],
+  "description": "The publication date printed beside the cite in the source note (YYYY-MM-DD) — \"89 FR 49102, June 11, 2024\" is 2024-06-11. Required with citation; its year is the volume + 1935."
+}

Added value: +{
+  "description": "Only documents carrying this docket number as the Federal Register prints it — a docketIds entry from a result here or from regulations_get_document, with or without a wrapper such as \"Docket No.\". Lists a docket's Federal Register documents with no REGULATIONS_GOV_API_KEY. A Regulations.gov docket ID matches only where the Federal Register prints it. Pass the complete number: a fragment (\"FAA-2026\") matches every docket that contains it.",
+  "type": "string"
+}

Previous value: -"Result order. Defaults to relevance with a query, newest without one. relevance without a query falls back to newest first; oldest lists the earliest publications first."New value: +"Result order. Defaults to relevance with a query, newest without one. relevance without a query falls back to newest first; oldest lists the earliest publications first. Ignored with citation, whose matches come in page order."

Added value: +{
+  "description": "Only documents carrying this Regulation Identifier Number — a regulationIdNumbers entry such as \"2040-AG18\", which follows one rulemaking from proposal to final rule. Pass the complete RIN: a fragment (\"2040\") matches every RIN that contains it.",
+  "type": "string"
+}

Previous value: -"Machine-readable failure mode. Declared by this tool: `upstream_unavailable`: Federal Register returned a 5xx, timed out, or served an HTML error page. `invalid_filter`: The Federal Register rejected a filter value — most often an agency name or acronym passed where a slug belongs. `date_range_inverted`: The start of a date range is later than its end. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `upstream_unavailable`: Federal Register returned a 5xx, timed out, or served an HTML error page. `invalid_filter`: The Federal Register rejected a filter value — most often an agency name or acronym passed where a slug belongs. `date_range_inverted`: The start of a date range is later than its end. `title_required_for_part`: cfr_part was given with no cfr_title. Part numbers repeat across titles, and the Federal Register rejects a part filter that names no title. `citation_incomplete`: citation or citation_date was given without the other, or together with published_after/published_before. `citation_out_of_range`: The cite's volume predates the Federal Register API (before volume 59, 1994), or citation_date falls in a different year from the volume. Other values are possible when a failure originates below the handler."

Previous value: -[
-  "upstream_unavailable",
-  "invalid_filter",
-  "date_range_inverted"
-]New value: +[
+  "upstream_unavailable",
+  "invalid_filter",
+  "date_range_inverted",
+  "title_required_for_part",
+  "citation_incomplete",
+  "citation_out_of_range"
+]

Added value: +{
+  "description": "Where the document starts in the Federal Register (\"89 FR 49101\"); null when none is recorded, as for most of 1994.",
+  "type": [
+    "string",
+    "null"
+  ]
+}

Added value: +{
+  "description": "Comments Regulations.gov received on this document, as the Federal Register reports it; null when not on Regulations.gov. Can exceed the comment records regulations_find_comments lists.",
+  "type": [
+    "number",
+    "null"
+  ]
+}

Added value: +{
+  "description": "Whether that comment period is open today: true through 11:59 PM Eastern on commentsCloseOn, false after it, null when commentsCloseOn is null.",
+  "type": [
+    "boolean",
+    "null"
+  ]
+}

Added value: +{
+  "description": "Regulations.gov page for submitting a comment on this document, as the Federal Register lists it. Null when it lists none, as it usually stops doing once the comment period closes.",
+  "type": [
+    "string",
+    "null"
+  ]
+}

Previous value: -"Comment-period close date (ISO 8601); when set, still open for comment."New value: +"Last day of the comment period this document printed (ISO 8601), inclusive, in Eastern time; null when it prints none. A later extension published as its own document is not reflected here."

Previous value: -"Docket IDs — chain into regulations_get_docket / regulations_find_comments."New value: +"Docket numbers as the Federal Register prints them — an agency's own number (\"REG-101355-26\"), or an ID inside a wrapper (\"Docket No. FAA-2026-8449\"). Pass one back as the docket_id filter. Not always a Regulations.gov ID: for regulations_get_docket / regulations_find_comments use regulationsGovDocketId."

Added value: +{
+  "description": "Last Federal Register page the document is printed on; null when unrecorded.",
+  "type": [
+    "number",
+    "null"
+  ]
+}

Added value: +{
+  "description": "Regulations.gov docket ID — chains into regulations_get_docket / regulations_find_comments(docket_id). Null when the document is not on Regulations.gov. An <AGENCY>_FRDOC_0001 docket (EPA_FRDOC_0001 holds 3,451 documents) is Regulations.gov's catch-all for Federal Register documents outside a rulemaking docket, so this document's comments come from regulationsGovDocumentId instead.",
+  "type": [
+    "string",
+    "null"
+  ]
+}

Added value: +{
+  "description": "Regulations.gov document ID — pass as document_object_id to regulations_find_comments for the comments filed on this document. Null when absent.",
+  "type": [
+    "string",
+    "null"
+  ]
+}

Added value: +{
+  "description": "First Federal Register page the document is printed on; null when unrecorded.",
+  "type": [
+    "number",
+    "null"
+  ]
+}

Previous value: -[
-  "documentNumber",
-  "title",
-  "type",
-  "abstract",
-  "publicationDate",
-  "agencies",
-  "docketIds",
-  "regulationIdNumbers",
-  "cfrReferences",
-  "commentsCloseOn",
-  "effectiveOn",
-  "htmlUrl"
-]New value: +[
+  "documentNumber",
+  "title",
+  "type",
+  "abstract",
+  "publicationDate",
+  "citation",
+  "startPage",
+  "endPage",
+  "agencies",
+  "docketIds",
+  "regulationsGovDocketId",
+  "regulationsGovDocumentId",
+  "commentCount",
+  "commentUrl",
+  "regulationIdNumbers",
+  "cfrReferences",
+  "commentsCloseOn",
+  "commentPeriodOpen",
+  "effectiveOn",
+  "htmlUrl"
+]

Previous value: -"Fetch one comment's full detail and attachments by its Regulations.gov comment ID (e.g. \"EPA-HQ-OAR-2025-0194-31102\"). Use to read a single comment's body after finding it in a list. Mutually exclusive with the other three targeting parameters — pass it alone, not alongside the docket it came from."New value: +"Fetch one comment's full detail and attachments by its Regulations.gov comment ID (e.g. \"EPA-HQ-OAR-2025-0194-31102\"). Use to read a single comment's body after finding it in a list. Mutually exclusive with the other three targeting parameters — pass it alone, not alongside the docket it came from — and takes none of the list filters."

Previous value: -"Fetch comments on one specific document by its Regulations.gov object ID (the objectId from regulations_get_docket's documents). Comments usually attach to the docket's primary (proposed-rule) document. Mutually exclusive with the other three targeting parameters."New value: +"Fetch comments on one specific Regulations.gov document, by either handle: its object ID, 16 hex characters (e.g. \"0900006485883ec6\", the objectId in regulations_get_docket's documents), or its document ID (e.g. \"EPA-HQ-OW-2022-0114-0027\", the regulationsGovDocumentId from regulations_get_document). Comments usually attach to the docket's primary (proposed-rule) document. Mutually exclusive with the other three targeting parameters."

Added value: +[
+  {
+    "const": "",
+    "type": "string"
+  },
+  {
+    "description": "Federal Register document number (e.g. \"2023-05471\", \"E9-25990\").",
+    "pattern": "^[A-Za-z]?[0-9]{1,4}-[0-9]{1,6}(-[0-9]{1,6})?$",
+    "type": "string"
+  }
+]

Previous value: -"Convenience: fetch comments for a Federal Register document by its FR number (e.g. \"2025-14555\"). Resolves to the Regulations.gov document internally. Saves a get_document → get_docket hop. Mutually exclusive with the other three targeting parameters."New value: +"Convenience: fetch comments on the Regulations.gov document carrying a Federal Register number (e.g. \"2023-05471\"; older numbers like \"E9-25990\" too). A Regulations.gov document ID (\"EPA-HQ-OW-2022-0114-0027\") is not an FR number; pass it as document_object_id. Saves a get_document → get_docket hop. A document that is not on Regulations.gov — a presidential document, for one — answers not_found. Mutually exclusive with the other three targeting parameters."

Removed value: -"string"

Previous value: -"Page number (1-based). Regulations.gov caps a query at 20 pages (5,000 records); for a high-volume docket this surfaces a sample — narrow by document_object_id."New value: +"Page number (1–40, default 1). Regulations.gov serves 40 pages, so a list reaches 40 × per_page comments (10,000 at per_page 250); totalPages and nextPage in the response say how far this one goes. To reach past that, take the set one posted_after/posted_before window at a time."

Previous value: -20New value: +40

Added value: +{
+  "anyOf": [
+    {
+      "const": "",
+      "type": "string"
+    },
+    {
+      "description": "ISO 8601 date (YYYY-MM-DD).",
+      "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
+      "type": "string"
+    }
+  ],
+  "description": "List mode: earliest posted date, inclusive, ISO 8601 (YYYY-MM-DD), a real calendar day. Pair with posted_before to take a high-volume set one window at a time."
+}

Added value: +{
+  "anyOf": [
+    {
+      "const": "",
+      "type": "string"
+    },
+    {
+      "description": "ISO 8601 date (YYYY-MM-DD).",
+      "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
+      "type": "string"
+    }
+  ],
+  "description": "List mode: latest posted date, inclusive, ISO 8601 (YYYY-MM-DD), a real calendar day. The same date as posted_after selects that one day."
+}

Added value: +{
+  "description": "List mode: keep only comments whose text matches, as Regulations.gov full-text search reads it — stemmed, so \"flaring\" also matches \"flare\" and \"flares\". Each hit then carries highlightedContent, the passages that matched.",
+  "type": "string"
+}

Added value: +{
+  "description": "The most comments 40 pages reach at this per_page (40 × per_page); set with truncated (list mode).",
+  "type": "number"
+}

Added value: +{
+  "description": "The passages of the comment text that matched search_term, as plain text — present only when search_term was given.",
+  "type": "string"
+}

Added value: +{
+  "description": "Identical submissions this record stands for. 0 or 1 is an ordinary submission, depending on the agency; above 1 marks a mass-mail campaign record standing for that many identical submissions. Null when not recorded (detail mode).",
+  "type": [
+    "number",
+    "null"
+  ]
+}

Previous value: -"Machine-readable failure mode. Declared by this tool: `auth_required`: REGULATIONS_GOV_API_KEY is not configured, or Regulations.gov rejected the key that is. `target_required`: None of docket_id / document_object_id / fr_document_number / comment_id was given. `multiple_targets`: More than one of docket_id / document_object_id / fr_document_number / comment_id was given. `not_found`: The target docket/document/comment has no comments or does not exist. `rate_limited`: Regulations.gov returned 429. `upstream_unavailable`: Regulations.gov returned a 5xx, timed out, or could not be reached at all. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `auth_required`: REGULATIONS_GOV_API_KEY is not configured, or Regulations.gov rejected the key that is. `target_required`: None of docket_id / document_object_id / fr_document_number / comment_id was given. `multiple_targets`: More than one of docket_id / document_object_id / fr_document_number / comment_id was given. `filter_requires_list_mode`: search_term, posted_after, or posted_before was given with comment_id, which reads one comment and takes no filters. `date_range_inverted`: The start of a date range is later than its end. `not_found`: The target docket, document, or comment does not exist on Regulations.gov, or no Regulations.gov document carries the FR number. `rate_limited`: Regulations.gov returned 429. `upstream_unavailable`: Regulations.gov returned a 5xx, timed out, or could not be reached at all. Other values are possible when a failure originates below the handler."

Previous value: -[
-  "auth_required",
-  "target_required",
-  "multiple_targets",
-  "not_found",
-  "rate_limited",
-  "upstream_unavailable"
-]New value: +[
+  "auth_required",
+  "target_required",
+  "multiple_targets",
+  "filter_requires_list_mode",
+  "date_range_inverted",
+  "not_found",
+  "rate_limited",
+  "upstream_unavailable"
+]

Added value: +{
+  "description": "Page to request next — present only when a later page holds comments (list mode).",
+  "type": "number"
+}

Previous value: -"Guidance — empty results, or that bodies need comment_id detail mode."New value: +"Guidance — no comments matched, the page is past the end, comments lie beyond the last page, or the substance of a comment is in its attachments."

Added value: +{
+  "description": "Postmark on a mailed submission, or null — many agencies record none (detail mode).",
+  "type": [
+    "string",
+    "null"
+  ]
+}

Previous value: -"Received date, or null (detail mode)."New value: +"Date Regulations.gov received the comment, or null when not recorded (detail mode)."

Previous value: -"What was queried — docket / document / FR doc (list mode)."New value: +"What was queried — the docket, document, or FR document, with any search_term and posted-date filters (list mode)."

Added value: +{
+  "description": "Pages of comments at this per_page, at most the 40 Regulations.gov serves; 0 when none matched (list mode).",
+  "type": "number"
+}

Previous value: -"True when comments exceed the 5,000-record ceiling (list mode)."New value: +"True when more comments matched than 40 pages reach at this per_page, so some are on no page — set on every page of such a set (list mode)."

Previous value: -"Page number (1-based). Regulations.gov caps a query at 20 pages (5,000 records); beyond that, narrow with document_types."New value: +"Page number (1–40, default 1). Regulations.gov serves 40 pages, so a docket listing reaches 40 × per_page documents (10,000 at per_page 250); totalPages and nextPage in the response say how far this one goes. Beyond that, narrow with document_types."

Previous value: -20New value: +40

Previous value: -[
-  {
-    "not": {
-      "required": [
-        "error"
-      ]
-    },
-    "required": [
-      "docketId",
-      "title",
-      "docketType",
-      "agencyId",
-      "rin",
-      "abstract",
-      "modifyDate",
-      "objectId",
-      "documentCount",
-      "documents"
-    ]
-  },
-  {
-    "required": [
-      "error"
-    ]
-  }
-]New value: +[
+  {
+    "not": {
+      "required": [
+        "error"
+      ]
+    },
+    "required": [
+      "docketId",
+      "title",
+      "docketType",
+      "agencyId",
+      "rin",
+      "abstract",
+      "modifyDate",
+      "objectId",
+      "documentCount",
+      "documents",
+      "totalPages"
+    ]
+  },
+  {
+    "required": [
+      "error"
+    ]
+  }
+]

Added value: +{
+  "description": "The most documents 40 pages reach at this per_page (40 × per_page); set with truncated.",
+  "type": "number"
+}

Added value: +{
+  "description": "Page to request next — present only when a later page holds documents.",
+  "type": "number"
+}

Previous value: -"Guidance when the docket has no documents."New value: +"Guidance when the docket has no documents, when the page is past the end, or when documents lie beyond the last page."

Added value: +{
+  "description": "Pages of documents at this per_page, at most the 40 Regulations.gov serves; 0 when there are none.",
+  "type": "number"
+}

Previous value: -"True when documentCount exceeds the returned set / 5,000 ceiling."New value: +"True when the docket holds more documents than 40 pages reach at this per_page, so some are on no page — set on every page of such a docket."

Previous value: -"Federal Register document number (e.g. \"2025-14555\"). Obtain from regulations_search_rules results (the documentNumber field)."New value: +"Federal Register document number, as regulations_search_rules returns it in documentNumber: \"2024-07773\" from 2010 on, older and correction numbers like \"98-1572\", \"E9-25990\", or \"C1-2009-30484\"."

Previous value: -"^[0-9]{4}-[0-9]+$"New value: +"^[A-Za-z]?[0-9]{1,4}-[0-9]{1,6}(-[0-9]{1,6})?$"

Previous value: -"Regulations.gov document ID — chain into regulations_find_comments (document-scoped). Null when absent."New value: +"Regulations.gov document ID — pass as document_object_id to regulations_find_comments for the comments filed on this document alone. Null when absent."

Previous value: -"Page number (1–50, default 1). The FR API caps total_pages at 50 — with per_page=100 this allows navigating up to 5,000 results. To reach beyond that window, narrow with published_after/published_before rather than paging deeper."New value: +"Page number (1–50, default 1). The Federal Register serves 50 pages, so a query reaches 50 × per_page matches (5,000 at per_page 100); totalPages and nextPage in the response say how far this one goes. To reach past that, narrow with published_after/published_before rather than paging deeper."

Previous value: -[
-  {
-    "not": {
-      "required": [
-        "error"
-      ]
-    },
-    "required": [
-      "results",
-      "totalCount"
-    ]
-  },
-  {
-    "required": [
-      "error"
-    ]
-  }
-]New value: +[
+  {
+    "not": {
+      "required": [
+        "error"
+      ]
+    },
+    "required": [
+      "results",
+      "totalCount",
+      "totalPages"
+    ]
+  },
+  {
+    "required": [
+      "error"
+    ]
+  }
+]

Added value: +{
+  "description": "The most matches 50 pages reach at this per_page (50 × per_page); set with truncated.",
+  "type": "number"
+}

Previous value: -"Machine-readable failure mode. Declared by this tool: `upstream_unavailable`: Federal Register returned a 5xx, timed out, or served an HTML error page. `invalid_filter`: The Federal Register rejected a filter value — most often an agency name or acronym passed where a slug belongs. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `upstream_unavailable`: Federal Register returned a 5xx, timed out, or served an HTML error page. `invalid_filter`: The Federal Register rejected a filter value — most often an agency name or acronym passed where a slug belongs. `date_range_inverted`: The start of a date range is later than its end. Other values are possible when a failure originates below the handler."

Previous value: -[
-  "upstream_unavailable",
-  "invalid_filter"
-]New value: +[
+  "upstream_unavailable",
+  "invalid_filter",
+  "date_range_inverted"
+]

Added value: +{
+  "description": "Page to request next — present only when a later page holds matches.",
+  "type": "number"
+}

Previous value: -"Guidance when nothing matched or when results were truncated."New value: +"Guidance when nothing matched, when the page is past the end, or when matches lie beyond the last page."

Previous value: -"Total matches before pagination (FR count; capped at 10,000 by the API window)."New value: +"Matches before pagination. The Federal Register stops counting at 10,000, so 10,000 means at least that many."

Added value: +{
+  "description": "Pages at this per_page, at most the 50 the Federal Register serves; 0 when nothing matched.",
+  "type": "number"
+}

Previous value: -"True when matches exceed the FR 50-page (5,000-record) navigation ceiling."New value: +"True when more documents matched than 50 pages reach at this per_page, so some are on no page — set on every page of such a set."

Previous value: -"Point-in-time date, ISO 8601 (YYYY-MM-DD). Defaults to current. Structure mode uses it for the historical hierarchy. Search mode matches only the section text in effect on that day, so a past date searches the CFR as it read then; eCFR indexes 2017-01-03 onward and rejects a date past its current index date."New value: +"Point-in-time date, ISO 8601 (YYYY-MM-DD). Defaults to current. Structure mode uses it for the historical hierarchy, and rejects a date past the title's up-to-date date. Search mode matches only the section text in effect on that day, so a past date searches the CFR as it read then; eCFR indexes 2017-01-03 onward and rejects a date past its current index date."

Previous value: -"\"structure\": browse the CFR tree (titles, or one title's chapters/parts/sections) to find a cite. \"search\": full-text search the codified CFR for sections matching a phrase."New value: +"\"structure\": list titles, a title's top-level divisions, or a part's sections and appendices, to find a cite. \"search\": full-text search the codified CFR for sections matching a phrase."

Added value: +{
+  "default": 1,
+  "description": "1-based page of search results, or of a part's listing in structure mode (default 1); ignored by a structure listing above a part, which comes back whole. A truncation notice names the next page. Live eCFR search pages through its first 10,000 hits only, so a page starting past them is refused — narrow the query instead of paging deeper.",
+  "maximum": 9007199254740991,
+  "minimum": 1,
+  "type": "integer"
+}

Previous value: -"CFR part within the title, in both modes — structure mode narrows the returned tree to that part's sections, search mode restricts matches to text inside that part. Requires title; a part on its own is rejected. Parts can be alphanumeric (\"1203a\", \"16A\") and are matched exactly, so pass the identifier as eCFR writes it — \"58\", not \"Part 58\" or \"058\"."New value: +"CFR part within the title, in both modes — structure mode lists every section and appendix in the part, flattened and paged by page/per_page; search mode restricts matches to text inside that part. Requires title; a part on its own is rejected. Parts can be alphanumeric (\"1203a\", \"16A\") and are matched exactly, so pass the identifier as eCFR writes it — \"58\", not \"Part 58\" or \"058\"."

Previous value: -"Results per page in search mode (1–50, default 20). Ignored in structure mode."New value: +"Rows per page — search results, or nodes of a part's listing in structure mode (1–50, default 20)."

Previous value: -"CFR title number (1–50). Structure mode: omit to list all 50 titles, or provide to expand one title. Search mode: optional filter restricting matches to that title — e.g. 40 for environmental rules, 21 for food and drugs."New value: +"CFR title number (1–50). Structure mode: omit to list all 50 titles; provide it alone to list the title's top-level divisions (chapters, or subtitles) — not the parts beneath them — or with part to list that part. Search mode: optional filter restricting matches to that title — e.g. 40 for environmental rules, 21 for food and drugs."

Added value: +{
+  "description": "What a search totalCount counts. \"sections\": distinct sections and appendices, one per result row. \"section_versions\": eCFR's own hit count, which counts every indexed version of each section — an upper bound on the rows the query pages through, reported until the whole hit list has been read.",
+  "enum": [
+    "sections",
+    "section_versions"
+  ],
+  "type": "string"
+}

Previous value: -"Machine-readable failure mode. Declared by this tool: `query_required`: mode=\"search\" with no query phrase. `title_not_found`: Structure mode where eCFR publishes no tree for the title at that date (a reserved title, or a date outside its coverage), or where the part is absent from the tree it does publish. `title_required_for_part`: A part was given with no title. Part identifiers repeat across titles, and eCFR rejects a part filter that names no title. `date_out_of_range`: Search mode with a date outside eCFR's indexed window (before 2017-01-03, or past its current index date). `upstream_unavailable`: eCFR returned a 5xx, timed out, or served an HTML error page (live path). Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `query_required`: mode=\"search\" with no query phrase. `title_not_found`: Structure mode where eCFR publishes no tree for the title at that date (a reserved title, or a date before its coverage), or where the part is absent from the tree it does publish. `title_required_for_part`: A part was given with no title. Part identifiers repeat across titles, and eCFR rejects a part filter that names no title. `date_out_of_range`: A date past what eCFR serves: in structure mode, past the title's up-to-date date; in search mode, outside the indexed window (before 2017-01-03, or past its current index date). `page_out_of_window`: A live search page that starts past the 10,000 hits eCFR pages through for one query. `upstream_unavailable`: eCFR returned a 5xx, timed out, or served an HTML error page (live path). Other values are possible when a failure originates below the handler."

Previous value: -[
-  "query_required",
-  "title_not_found",
-  "title_required_for_part",
-  "date_out_of_range",
-  "upstream_unavailable"
-]New value: +[
+  "query_required",
+  "title_not_found",
+  "title_required_for_part",
+  "date_out_of_range",
+  "page_out_of_window",
+  "upstream_unavailable"
+]

Previous value: -"Hierarchy nodes at the requested level (structure mode)."New value: +"Structure mode: the 50 titles, a title's top-level divisions, or this page of a part's sections and appendices in document order."

Previous value: -"Assembled cite → regulations_get_cfr_section: \"40 CFR 50\" / \"40 CFR 50.1\" for a part or section, \"Appendix A-1 to Part 50, Title 40\" for an appendix. Null on a level with no read path (chapter, subchapter, subpart, subject group)."New value: +"Assembled cite → regulations_get_cfr_section: \"40 CFR 50.1\" for a section, \"Appendix A-1 to Part 50, Title 40\" for an appendix. Null on a level with no read path (title, subtitle, chapter)."

Previous value: -"Node identifier (e.g. \"40\", \"I\", \"50\", \"50.1\")."New value: +"Node identifier (e.g. \"40\", \"I\", \"50.1\")."

Previous value: -"Human-readable label."New value: +"Human-readable label, plain text."

Added value: +{
+  "description": "In a part listing, the heading of the subject group the node sits under (a group of sections inside a part or subpart); null when it sits in none, and on every node above a part.",
+  "type": [
+    "string",
+    "null"
+  ]
+}

Added value: +{
+  "description": "In a part listing, the label of the subpart the node sits under (\"Subpart A—General\"); null when no subpart encloses it, and on every node above a part.",
+  "type": [
+    "string",
+    "null"
+  ]
+}

Previous value: -"Node type: title, chapter, subchapter, subpart, part, section, appendix, subject_group, or other (treat unknown types as passthrough)."New value: +"Node type: title, subtitle, or chapter above a part; section or appendix in a part listing. Treat an unknown type as passthrough."

Previous value: -[
-  "type",
-  "identifier",
-  "label",
-  "description",
-  "reserved",
-  "cfrCite",
-  "appendix"
-]New value: +[
+  "type",
+  "identifier",
+  "label",
+  "description",
+  "reserved",
+  "cfrCite",
+  "appendix",
+  "subpart",
+  "subjectGroup"
+]

Previous value: -"Guidance when nothing matched."New value: +"Guidance: the next page to request, a page past the end, an empty result, or what the count means."

Added value: +{
+  "description": "The page served — of search results, or of a part's listing.",
+  "type": "number"
+}

Previous value: -"Matching CFR sections, this page (search mode)."New value: +"Matching CFR sections and appendices, this page, one row per section however many of its versions matched (search mode)."

Previous value: -"Results returned on this page (search mode)."New value: +"Rows returned on this page."

Previous value: -"Total search matches before pagination (search mode)."New value: +"Total matches before pagination — search results (see countBasis for what they count), or the nodes in a part's listing."

Previous value: -"True when search results were capped at per_page."New value: +"True when another page follows this one."

Previous value: -"Point-in-time date, ISO 8601 (YYYY-MM-DD). Default current. eCFR retains historical versions back to ~2017; a date before coverage is rejected."New value: +"Point-in-time date, ISO 8601 (YYYY-MM-DD). Default current. eCFR serves 2017-01-01 through the title's up-to-date date, usually a few days behind today; a date outside that window is rejected, naming the window."

Added value: +{
+  "description": "Most text characters to return in this window (1–200,000, default 64,000).",
+  "maximum": 200000,
+  "minimum": 1,
+  "type": "integer"
+}

Added value: +{
+  "description": "Character offset into the text where the window starts (default 0). Pass bodyTextNextOffset from the previous call to read on, or a sections[].offset from a whole-part read to jump to that section.",
+  "maximum": 9007199254740991,
+  "minimum": 0,
+  "type": "integer"
+}

Previous value: -"Section identifier within the part (e.g. \"50.1\"). Omit to fetch the entire part — large parts can be very long; prefer a specific section when you know it. Cannot be combined with appendix."New value: +"Section within the part, normally written part.section as eCFR identifies it (\"141.61\"). Also accepted: the number alone (\"61\" in part 141), a leading \"§\" or \"Sec.\", and a paragraph cite (\"141.61(c)\"), which reads the whole section. Identifiers eCFR writes differently are read as given — 14 CFR 241 numbers its sections \"25\" and \"1-1\". Omit to fetch the entire part. Cannot be combined with appendix."

Previous value: -[
-  {
-    "not": {
-      "required": [
-        "error"
-      ]
-    },
-    "required": [
-      "cfrCite",
-      "title",
-      "part",
-      "section",
-      "appendix",
-      "heading",
-      "hierarchyPath",
-      "date",
-      "source",
-      "bodyText"
-    ]
-  },
-  {
-    "required": [
-      "error"
-    ]
-  }
-]New value: +[
+  {
+    "not": {
+      "required": [
+        "error"
+      ]
+    },
+    "required": [
+      "cfrCite",
+      "title",
+      "part",
+      "section",
+      "appendix",
+      "heading",
+      "hierarchyPath",
+      "date",
+      "source",
+      "bodyText",
+      "bodyTextOffset",
+      "bodyTextLength"
+    ]
+  },
+  {
+    "required": [
+      "error"
+    ]
+  }
+]

Previous value: -"Text of the section, part, or appendix, XML stripped to plain text. Paragraphs, subheadings, editorial notes, tables (one pipe-delimited line per row), figure references (\"[Figure: /graphics/…]\"), and the trailing source citation are kept in document order. The source citation is the bracketed Federal Register history the text ends in (\"[36 FR 22384, Nov. 25, 1971, as amended at 81 FR 68276, Oct. 3, 2016]\") — pass one of its FR cites to regulations_search_rules to reach the rulemaking that produced this text. Empty only where the location is a placeholder carrying nothing but its heading — \"[Reserved]\", or an agency variant of it."New value: +"One window of the location's text, starting at bodyTextOffset, XML stripped to plain text. A whole part's text is each section's heading and body in order. Paragraphs, subheadings, editorial notes, tables (one pipe-delimited line per row), figure references (\"[Figure: /graphics/…]\"), and each section's trailing source citation are kept in document order. The source citation is the bracketed Federal Register history a section ends in (\"[36 FR 22384, Nov. 25, 1971, as amended at 81 FR 68276, Oct. 3, 2016]\") — pass one of its FR cites to regulations_search_rules to reach the rulemaking that produced this text. Empty when the offset is at or past the end, or where the location is a placeholder carrying nothing but its heading (\"[Reserved]\")."

Added value: +{
+  "description": "Characters in the location's whole text.",
+  "type": "number"
+}

Added value: +{
+  "description": "Offset to pass as offset to read the next window — present only when text remains past this window.",
+  "type": "number"
+}

Added value: +{
+  "description": "Character offset bodyText starts at.",
+  "type": "number"
+}

Previous value: -"Machine-readable failure mode. Declared by this tool: `not_found`: No such title/part/section/appendix at that date. `location_required`: Neither part nor appendix was given, so the call names no location to read. `conflicting_target`: Both section and appendix were given. They name two different locations, and picking one silently would return text the call did not ask for. `date_out_of_range`: The requested date precedes eCFR historical coverage. `upstream_unavailable`: eCFR returned a 5xx, timed out, or served an HTML error page (live path). Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `not_found`: No such title/part/section/appendix at that date, under the section as given or any form it resolves to. `location_required`: Neither part nor appendix was given, so the call names no location to read. `conflicting_target`: Both section and appendix were given. They name two different locations, and picking one silently would return text the call did not ask for. `date_out_of_range`: The requested date precedes eCFR historical coverage (2017-01-01) or is past the title's up-to-date date. `upstream_unavailable`: eCFR returned a 5xx, timed out, or served an HTML error page (live path). Other values are possible when a failure originates below the handler."

Added value: +{
+  "description": "How a section written another way was resolved, and guidance when the offset is at or past the end of the text.",
+  "type": "string"
+}

Previous value: -"Section identifier; null when a whole part or an appendix was fetched."New value: +"Section identifier that was read — the resolved form when the input was written differently (\"141.61\" for \"§ 141.61(c)\"); null when a whole part or an appendix was fetched."

Previous value: -"Present only when a whole part was fetched — each section in the part."New value: +"Present only on a whole-part fetch — the part's sections whose text falls in this window, in order, without their text (bodyText carries it). A section that begins before the window and runs into it is included, so its offset can be below bodyTextOffset. Empty when the offset is past the end. To list every section and appendix of a part without reading its text, use regulations_browse_cfr in structure mode with title and part."

Previous value: -"One section within the part."New value: +"One section of the part, without its text."

Removed value: -{
-  "description": "Section text.",
-  "type": "string"
-}

Added value: +{
+  "description": "Assembled cite for the section.",
+  "type": "string"
+}

Added value: +{
+  "description": "Offset in the whole part's text where this section starts — pass as offset to read from it.",
+  "type": "number"
+}

Previous value: -"Section identifier."New value: +"Section identifier — pass as section to read it alone."

Previous value: -[
-  "section",
-  "heading",
-  "bodyText"
-]New value: +[
+  "section",
+  "heading",
+  "cfrCite",
+  "offset"
+]

Removed value: -false

Previous value: -"When true, fetch and inline the document body as plain text (can be large). Default false returns the body URLs only; fetch full text only when you need to read the rule itself, not just its metadata and cross-links."New value: +"When true, inline one window of the document body as plain text (see offset and max_chars). Omitted, the body URLs alone come back unless offset or max_chars is passed; fetch full text only when you need to read the rule itself, not just its metadata and cross-links."

Added value: +{
+  "description": "Most body characters to return in this window (1–200,000, default 64,000). Implies include_full_text.",
+  "maximum": 200000,
+  "minimum": 1,
+  "type": "integer"
+}

Added value: +{
+  "description": "Character offset into the plain-text body where the window starts (default 0). Pass the fullTextNextOffset from the previous call to read on. Implies include_full_text.",
+  "maximum": 9007199254740991,
+  "minimum": 0,
+  "type": "integer"
+}

Previous value: -"Issuing agency names."New value: +"Issuing agencies."

Added value: +false

Added value: +"One issuing agency."

Added value: +{
+  "name": {
+    "description": "Agency name.",
+    "type": "string"
+  },
+  "slug": {
+    "description": "Federal Register agency slug — the value the agencies filter on regulations_search_rules and regulations_list_open_comments takes. Null when the Federal Register lists the agency by raw name only.",
+    "type": [
+      "string",
+      "null"
+    ]
+  }
+}

Added value: +[
+  "name",
+  "slug"
+]

Previous value: -"string"New value: +"object"

Previous value: -"Machine-readable failure mode. Declared by this tool: `not_found`: No Federal Register document exists with that number. `upstream_unavailable`: Federal Register returned a 5xx, timed out, served an HTML error page, or failed to serve the body URL it published (include_full_text only). Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `full_text_disabled`: offset or max_chars was passed together with include_full_text: false. `not_found`: No Federal Register document exists with that number. `upstream_unavailable`: Federal Register returned a 5xx, timed out, served an HTML error page, or failed to serve the body URL it published (include_full_text only). Other values are possible when a failure originates below the handler."

Previous value: -[
-  "not_found",
-  "upstream_unavailable"
-]New value: +[
+  "full_text_disabled",
+  "not_found",
+  "upstream_unavailable"
+]

Previous value: -"Inlined plain-text body — present only when include_full_text=true."New value: +"One window of the plain-text body, starting at fullTextOffset — present only when full text was requested. Empty when the offset is at or past the end."

Added value: +{
+  "description": "Characters in the whole plain-text body — present with fullText.",
+  "type": "number"
+}

Added value: +{
+  "description": "Offset to pass as offset to read the next window — present only when body text remains past this window.",
+  "type": "number"
+}

Added value: +{
+  "description": "Character offset fullText starts at — present with fullText.",
+  "type": "number"
+}

Added value: +{
+  "description": "Guidance when the requested offset is at or past the end of the body.",
+  "type": "string"
+}

Previous value: -"Filter to one or more agencies by Federal Register agency slug (e.g. \"environmental-protection-agency\")."New value: +"Filter to one or more agencies by Federal Register agency slug (e.g. \"environmental-protection-agency\") — lowercase kebab-case, not a name or acronym. Every row lists its agencies with their slugs; read agencies[].slug off a row here or in regulations_search_rules. One unrecognized slug fails the whole request."

Previous value: -"Only rules whose comment period closes on or before this date, ISO 8601 (YYYY-MM-DD). Use to find deadlines you need to act on soon."New value: +"Only documents whose comment period closes on or before this date, ISO 8601 (YYYY-MM-DD), a real calendar day. Use to find deadlines you need to act on soon."

Previous value: -"Page number (1–50). The FR caps total_pages at 50; with per_page=100 this covers up to 5,000 open rules."New value: +"Page number, default 1. Pages run over the whole open window in closing-date order; totalPages and nextPage in the response say how far it goes."

Previous value: -50New value: +10000

Previous value: -"Results per page (2–100, default 20). The Federal Register API treats exactly 1 as its default page size instead of returning one result."New value: +"Documents per page (1–100, default 20)."

Previous value: -2New value: +1

Previous value: -"Full-text filter across open rules. Omit to list all rules currently open for comment."New value: +"Full-text filter across open documents. Omit to list every document currently open for comment."

Added value: +{
+  "description": "Document types to include: PRORULE (proposed rules), RULE (final rules that request comment, including direct final and interim final rules), NOTICE (information-collection and other notices with comment periods — a much larger set). Default, and when empty: [\"PRORULE\", \"RULE\"].",
+  "items": {
+    "enum": [
+      "PRORULE",
+      "RULE",
+      "NOTICE"
+    ],
+    "type": "string"
+  },
+  "type": "array"
+}

Previous value: -[
-  {
-    "not": {
-      "required": [
-        "error"
-      ]
-    },
-    "required": [
-      "asOf",
-      "keyed",
-      "results",
-      "totalCount"
-    ]
-  },
-  {
-    "required": [
-      "error"
-    ]
-  }
-]New value: +[
+  {
+    "not": {
+      "required": [
+        "error"
+      ]
+    },
+    "required": [
+      "asOf",
+      "keyed",
+      "results",
+      "totalCount",
+      "totalPages"
+    ]
+  },
+  {
+    "required": [
+      "error"
+    ]
+  }
+]

Added value: +{
+  "description": "The Federal Register document limit that was reached.",
+  "type": "number"
+}

Previous value: -"Machine-readable failure mode. Declared by this tool: `upstream_unavailable`: Federal Register returned a 5xx, timed out, or served an HTML error page. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `upstream_unavailable`: Federal Register returned a 5xx, timed out, or served an HTML error page. `invalid_filter`: The Federal Register rejected a filter value — most often an agency name or acronym passed where a slug belongs. Other values are possible when a failure originates below the handler."

Previous value: -[
-  "upstream_unavailable"
-]New value: +[
+  "upstream_unavailable",
+  "invalid_filter"
+]

Added value: +{
+  "description": "Page to request next — present only when documents remain past this page.",
+  "type": "number"
+}

Previous value: -"Guidance when nothing matched, or that comment counts are unavailable without a key."New value: +"Guidance when nothing matched, when the page is past the end, when the window was truncated, or that comment counts are unavailable without a key."

Previous value: -"Rules open for comment (this page), closing soonest first."New value: +"Documents open for comment on this page, closing soonest first; documents closing the same day are ordered by document number."

Previous value: -"One open-for-comment rule."New value: +"One document open for comment."

Previous value: -"Issuing agency names."New value: +"Issuing agencies."

Added value: +false

Added value: +"One issuing agency."

Added value: +{
+  "name": {
+    "description": "Agency name.",
+    "type": "string"
+  },
+  "slug": {
+    "description": "Federal Register agency slug — pass it back as the agencies filter. Null when the Federal Register lists the agency by raw name only, so it cannot be filtered on.",
+    "type": [
+      "string",
+      "null"
+    ]
+  }
+}

Added value: +[
+  "name",
+  "slug"
+]

Previous value: -"string"New value: +"object"

Previous value: -"Rule title."New value: +"Document title."

Previous value: -"Document type."New value: +"Document type — \"Proposed Rule\", \"Rule\", or \"Notice\"; \"Unknown\" when unlisted."

Previous value: -"Results returned on this page."New value: +"Documents returned on this page."

Previous value: -"Total rules open for comment matching the filters."New value: +"Documents open for comment matching the filters — the window the pages run over."

Added value: +{
+  "description": "Pages in the window at this per_page.",
+  "type": "number"
+}

Previous value: -"True when matches exceed the FR 5,000-record navigation ceiling."New value: +"True when the Federal Register reported its 10,000-document maximum, so the window holds only the 10,000 most recently published matches."

Previous value: -"Filter to one or more agencies by Federal Register agency slug (e.g. \"environmental-protection-agency\", \"securities-and-exchange-commission\"). Slugs are the kebab-case agency name; if unsure, search by query and read the agency slugs off the results."New value: +"Filter to one or more agencies by Federal Register agency slug (e.g. \"environmental-protection-agency\", \"securities-and-exchange-commission\") — lowercase kebab-case, not a name or acronym. Every result lists its agencies with their slugs; if unsure, search by query and read agencies[].slug off a result. One unrecognized slug fails the whole request."

Added value: +{
+  "description": "Result order. Defaults to relevance with a query, newest without one. relevance without a query falls back to newest first; oldest lists the earliest publications first.",
+  "enum": [
+    "relevance",
+    "newest",
+    "oldest"
+  ],
+  "type": "string"
+}

Previous value: -"Earliest publication date, ISO 8601 (YYYY-MM-DD). Combine with published_before to window large result sets — the FR caps navigation at 50 pages."New value: +"Earliest publication date, ISO 8601 (YYYY-MM-DD), a real calendar day. Combine with published_before to window large result sets — the FR caps navigation at 50 pages."

Previous value: -"Latest publication date, ISO 8601 (YYYY-MM-DD)."New value: +"Latest publication date, ISO 8601 (YYYY-MM-DD), a real calendar day."

Previous value: -"Machine-readable failure mode. Declared by this tool: `upstream_unavailable`: Federal Register returned a 5xx, timed out, or served an HTML error page. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `upstream_unavailable`: Federal Register returned a 5xx, timed out, or served an HTML error page. `invalid_filter`: The Federal Register rejected a filter value — most often an agency name or acronym passed where a slug belongs. Other values are possible when a failure originates below the handler."

Previous value: -[
-  "upstream_unavailable"
-]New value: +[
+  "upstream_unavailable",
+  "invalid_filter"
+]

Previous value: -"Issuing agency names."New value: +"Issuing agencies."

Added value: +false

Added value: +"One issuing agency."

Added value: +{
+  "name": {
+    "description": "Agency name.",
+    "type": "string"
+  },
+  "slug": {
+    "description": "Federal Register agency slug — pass it back as the agencies filter. Null when the Federal Register lists the agency by raw name only, so it cannot be filtered on.",
+    "type": [
+      "string",
+      "null"
+    ]
+  }
+}

Added value: +[
+  "name",
+  "slug"
+]

Previous value: -"string"New value: +"object"

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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": [
+      "mode"
+    ]
+  },
+  {
+    "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: `query_required`: mode=\"search\" with no query phrase. `title_not_found`: Structure mode where eCFR publishes no tree for the title at that date (a reserved title, or a date outside its coverage), or where the part is absent from the tree it does publish. `title_required_for_part`: A part was given with no title. Part identifiers repeat across titles, and eCFR rejects a part filter that names no title. `date_out_of_range`: Search mode with a date outside eCFR's indexed window (before 2017-01-03, or past its current index date). `upstream_unavailable`: eCFR returned a 5xx, timed out, or served an HTML error page (live path). Other values are possible when a failure originates below the handler.",
+          "examples": [
+            "query_required",
+            "title_not_found",
+            "title_required_for_part",
+            "date_out_of_range",
+            "upstream_unavailable"
+          ],
+          "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: -[
-  "mode"
-]

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": [
+      "mode"
+    ]
+  },
+  {
+    "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: `auth_required`: REGULATIONS_GOV_API_KEY is not configured, or Regulations.gov rejected the key that is. `target_required`: None of docket_id / document_object_id / fr_document_number / comment_id was given. `multiple_targets`: More than one of docket_id / document_object_id / fr_document_number / comment_id was given. `not_found`: The target docket/document/comment has no comments or does not exist. `rate_limited`: Regulations.gov returned 429. `upstream_unavailable`: Regulations.gov returned a 5xx, timed out, or could not be reached at all. Other values are possible when a failure originates below the handler.",
+          "examples": [
+            "auth_required",
+            "target_required",
+            "multiple_targets",
+            "not_found",
+            "rate_limited",
+            "upstream_unavailable"
+          ],
+          "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: -[
-  "mode"
-]

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": [
+      "cfrCite",
+      "title",
+      "part",
+      "section",
+      "appendix",
+      "heading",
+      "hierarchyPath",
+      "date",
+      "source",
+      "bodyText"
+    ]
+  },
+  {
+    "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`: No such title/part/section/appendix at that date. `location_required`: Neither part nor appendix was given, so the call names no location to read. `conflicting_target`: Both section and appendix were given. They name two different locations, and picking one silently would return text the call did not ask for. `date_out_of_range`: The requested date precedes eCFR historical coverage. `upstream_unavailable`: eCFR returned a 5xx, timed out, or served an HTML error page (live path). Other values are possible when a failure originates below the handler.",
+          "examples": [
+            "not_found",
+            "location_required",
+            "conflicting_target",
+            "date_out_of_range",
+            "upstream_unavailable"
+          ],
+          "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: -[
-  "cfrCite",
-  "title",
-  "part",
-  "section",
-  "appendix",
-  "heading",
-  "hierarchyPath",
-  "date",
-  "source",
-  "bodyText"
-]

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": [
+      "docketId",
+      "title",
+      "docketType",
+      "agencyId",
+      "rin",
+      "abstract",
+      "modifyDate",
+      "objectId",
+      "documentCount",
+      "documents"
+    ]
+  },
+  {
+    "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: `auth_required`: REGULATIONS_GOV_API_KEY is not configured, or Regulations.gov rejected the key that is. `not_found`: No docket exists with that ID. `rate_limited`: Regulations.gov returned 429 (1,000 requests/hour per key). `upstream_unavailable`: Regulations.gov returned a 5xx, timed out, or could not be reached at all. Other values are possible when a failure originates below the handler.",
+          "examples": [
+            "auth_required",
+            "not_found",
+            "rate_limited",
+            "upstream_unavailable"
+          ],
+          "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: -[
-  "docketId",
-  "title",
-  "docketType",
-  "agencyId",
-  "rin",
-  "abstract",
-  "modifyDate",
-  "objectId",
-  "documentCount",
-  "documents"
-]

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": [
+      "documentNumber",
+      "title",
+      "type",
+      "abstract",
+      "action",
+      "dates",
+      "publicationDate",
+      "effectiveOn",
+      "commentsCloseOn",
+      "agencies",
+      "regulationIdNumbers",
+      "cfrReferences",
+      "docketId",
+      "regulationsGovDocumentId",
+      "commentCount",
+      "supportingDocuments",
+      "bodyHtmlUrl",
+      "rawTextUrl",
+      "htmlUrl"
+    ]
+  },
+  {
+    "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`: No Federal Register document exists with that number. `upstream_unavailable`: Federal Register returned a 5xx, timed out, served an HTML error page, or failed to serve the body URL it published (include_full_text only). Other values are possible when a failure originates below the handler.",
+          "examples": [
+            "not_found",
+            "upstream_unavailable"
+          ],
+          "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: -[
-  "documentNumber",
-  "title",
-  "type",
-  "abstract",
-  "action",
-  "dates",
-  "publicationDate",
-  "effectiveOn",
-  "commentsCloseOn",
-  "agencies",
-  "regulationIdNumbers",
-  "cfrReferences",
-  "docketId",
-  "regulationsGovDocumentId",
-  "commentCount",
-  "supportingDocuments",
-  "bodyHtmlUrl",
-  "rawTextUrl",
-  "htmlUrl"
-]

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

Added value: +false

Previous value: -"Results per page (1–100, default 20)."New value: +"Results per page (2–100, default 20). The Federal Register API treats exactly 1 as its default page size instead of returning one result."

Previous value: -1New value: +2

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": [
+      "asOf",
+      "keyed",
+      "results",
+      "totalCount"
+    ]
+  },
+  {
+    "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: `upstream_unavailable`: Federal Register returned a 5xx, timed out, or served an HTML error page. Other values are possible when a failure originates below the handler.",
+          "examples": [
+            "upstream_unavailable"
+          ],
+          "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: -[
-  "asOf",
-  "keyed",
-  "results",
-  "totalCount"
-]

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

Added value: +false

Previous value: -"Results per page (1–100, default 20)."New value: +"Results per page (2–100, default 20). The Federal Register API treats exactly 1 as its default page size instead of returning one result."

Previous value: -1New value: +2

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": [
+      "results",
+      "totalCount"
+    ]
+  },
+  {
+    "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: `upstream_unavailable`: Federal Register returned a 5xx, timed out, or served an HTML error page. Other values are possible when a failure originates below the handler.",
+          "examples": [
+            "upstream_unavailable"
+          ],
+          "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: -[
-  "results",
-  "totalCount"
-]

Previous value: -"Text of the section, part, or appendix, XML stripped to plain text. Paragraphs, subheadings, editorial notes, and tables (one pipe-delimited line per row) are kept in document order. Empty for a reserved appendix and for one whose whole content is a figure image."New value: +"Text of the section, part, or appendix, XML stripped to plain text. Paragraphs, subheadings, editorial notes, tables (one pipe-delimited line per row), figure references (\"[Figure: /graphics/…]\"), and the trailing source citation are kept in document order. The source citation is the bracketed Federal Register history the text ends in (\"[36 FR 22384, Nov. 25, 1971, as amended at 81 FR 68276, Oct. 3, 2016]\") — pass one of its FR cites to regulations_search_rules to reach the rulemaking that produced this text. Empty only where the location is a placeholder carrying nothing but its heading — \"[Reserved]\", or an agency variant of it."

Added value: +{
+  "anyOf": [
+    {
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "description": "On an appendix node, the identifier to pass straight back as regulations_get_cfr_section's `appendix` input; null on every other node type. It is free-form prose, not a letter (\"Schedule I to Part 789\", \"Special Federal Aviation Regulation No. 88\"), so pass it verbatim rather than abbreviating it."
+}

Previous value: -"Assembled cite for a part/section → regulations_get_cfr_section; null otherwise."New value: +"Assembled cite → regulations_get_cfr_section: \"40 CFR 50\" / \"40 CFR 50.1\" for a part or section, \"Appendix A-1 to Part 50, Title 40\" for an appendix. Null on a level with no read path (chapter, subchapter, subpart, subject group)."

Previous value: -[
-  "type",
-  "identifier",
-  "label",
-  "description",
-  "reserved",
-  "cfrCite"
-]New value: +[
+  "type",
+  "identifier",
+  "label",
+  "description",
+  "reserved",
+  "cfrCite",
+  "appendix"
+]

Previous value: -"One matching CFR section."New value: +"One matching CFR section or appendix."

Added value: +{
+  "anyOf": [
+    {
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "description": "On an appendix hit, the identifier to pass straight back as regulations_get_cfr_section's `appendix` input; null on a section hit. Always null on a mirror hit — the index holds section text only, so mirror-sourced results never match an appendix."
+}

Previous value: -"Assembled cite → regulations_get_cfr_section."New value: +"Assembled cite → regulations_get_cfr_section. A section hit cites the section (\"40 CFR 51.190\"); an appendix hit cites the appendix in eCFR's own form (\"Appendix C to Part 58, Title 40\"), not the part around it, since the part's sections do not contain the matched text."

Previous value: -[
-  "title",
-  "part",
-  "section",
-  "heading",
-  "hierarchyPath",
-  "excerpt",
-  "cfrCite"
-]New value: +[
+  "title",
+  "part",
+  "section",
+  "appendix",
+  "heading",
+  "hierarchyPath",
+  "excerpt",
+  "cfrCite"
+]

Added value: +{
+  "anyOf": [
+    {
+      "const": "",
+      "type": "string"
+    },
+    {
+      "description": "Appendix identifier (e.g. \"Appendix A-1 to Part 50\").",
+      "type": "string"
+    }
+  ],
+  "description": "Appendix identifier, verbatim as eCFR writes it — the `appendix` field or the leading phrase of the `cfrCite` on a regulations_browse_cfr appendix node or search hit. It is free-form prose, not a letter: \"Appendix A-1 to Part 50\", \"Appendix A to Subpart C of Part 4\", \"Schedule I to Part 789\", \"Special Federal Aviation Regulation No. 88\". Pass the whole phrase; a short form such as \"A-1\" matches nothing. Cannot be combined with section."
+}

Previous value: -"CFR part within the title (e.g. \"50\"). Parts can be alphanumeric. Obtain from regulations_browse_cfr or a Federal Register document's cfrReferences."New value: +"CFR part within the title (e.g. \"50\"). Parts can be alphanumeric. Required unless appendix is given, where it is optional but recommended: an appendix identifier is unique within a part, not within a title, so without a part eCFR picks one of the matches. Obtain from regulations_browse_cfr or a Federal Register document's cfrReferences."

Previous value: -"Section identifier within the part (e.g. \"50.1\"). Omit to fetch the entire part — large parts can be very long; prefer a specific section when you know it."New value: +"Section identifier within the part (e.g. \"50.1\"). Omit to fetch the entire part — large parts can be very long; prefer a specific section when you know it. Cannot be combined with appendix."

Previous value: -[
-  "title",
-  "part"
-]New value: +[
+  "title"
+]

Added value: +{
+  "description": "Present on a whole-part fetch when the part has appendices — their identifiers and headings, without their text. A part's appendices routinely run several times the length of its sections, so they are not inlined; call this tool again with `appendix` set to one of these identifiers to read it. Absent means the part has no appendices; a single-section or appendix fetch never carries this field.",
+  "items": {
+    "additionalProperties": false,
+    "description": "One appendix in the part, named but not inlined.",
+    "properties": {
+      "appendix": {
+        "description": "Appendix identifier, for a follow-up read.",
+        "type": "string"
+      },
+      "heading": {
+        "description": "Appendix heading.",
+        "type": "string"
+      }
+    },
+    "required": [
+      "appendix",
+      "heading"
+    ],
+    "type": "object"
+  },
+  "type": "array"
+}

Added value: +{
+  "anyOf": [
+    {
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "description": "Appendix identifier; null when a section or whole part was fetched."
+}

Previous value: -"Section text, XML stripped to plain text (paragraph structure preserved)."New value: +"Text of the section, part, or appendix, XML stripped to plain text. Paragraphs, subheadings, editorial notes, and tables (one pipe-delimited line per row) are kept in document order. Empty for a reserved appendix and for one whose whole content is a figure image."

Previous value: -"Assembled cite, e.g. \"40 CFR 50.1\"."New value: +"Assembled cite — \"40 CFR 50.1\" for a section, \"40 CFR 50\" for a part, \"Appendix A-1 to Part 50, Title 40\" for an appendix (eCFR's own form, leading with the identifier this tool takes back as `appendix`)."

Previous value: -"Section/part heading."New value: +"Section, part, or appendix heading."

Added value: +[
+  {
+    "type": "string"
+  },
+  {
+    "type": "null"
+  }
+]

Previous value: -"CFR part."New value: +"CFR part; null only for an appendix that hangs off a chapter, subchapter, or subtitle rather than a part."

Removed value: -"string"

Previous value: -"Section identifier; null when a whole part was fetched."New value: +"Section identifier; null when a whole part or an appendix was fetched."

Previous value: -[
-  "cfrCite",
-  "title",
-  "part",
-  "section",
-  "heading",
-  "hierarchyPath",
-  "date",
-  "source",
-  "bodyText"
-]New value: +[
+  "cfrCite",
+  "title",
+  "part",
+  "section",
+  "appendix",
+  "heading",
+  "hierarchyPath",
+  "date",
+  "source",
+  "bodyText"
+]

Previous value: -"CFR part within the title (structure mode, optional) — narrows the returned tree to one part's sections. Parts can be alphanumeric."New value: +"CFR part within the title, in both modes — structure mode narrows the returned tree to that part's sections, search mode restricts matches to text inside that part. Requires title; a part on its own is rejected. Parts can be alphanumeric (\"1203a\", \"16A\") and are matched exactly, so pass the identifier as eCFR writes it — \"58\", not \"Part 58\" or \"058\"."

Previous value: -"Structural path down to the match, e.g. \"Title 40 › Chapter I › Part 51 › § 51.190\"."New value: +"Path down to the match. A live hit names the part it sits in — \"Title 40 › Chapter I › Subchapter C › Part 51 — Requirements for Preparation, Adoption, and Submittal of Implementation Plans › § 51.190\" — so the subject matter is readable without a second call. A mirror hit is structural only (\"Title 14 › Part 25 › § 25.1043\"): the index stores no level names. Check `source` before comparing paths across results."

Previous value: -"What the answering corpus covers — the mirror's title coverage, or the live index and the date it was read at (search mode). Read it before concluding a query found nothing."New value: +"What the answering corpus covers — the mirror's title coverage, or the live index and the date it was read at — narrowed by whichever of title and part the call supplied (search mode). Read it before concluding a query found nothing."

Previous value: -"Fetch one comment's full detail and attachments by its Regulations.gov comment ID (e.g. \"EPA-HQ-OAR-2025-0194-31102\"). Use to read a single comment's body after finding it in a list."New value: +"Fetch one comment's full detail and attachments by its Regulations.gov comment ID (e.g. \"EPA-HQ-OAR-2025-0194-31102\"). Use to read a single comment's body after finding it in a list. Mutually exclusive with the other three targeting parameters — pass it alone, not alongside the docket it came from."

Previous value: -"Fetch all comments in a docket by docket ID (e.g. \"EPA-HQ-OAR-2025-0194\"). Broadest scope. One of docket_id / document_object_id / fr_document_number / comment_id is required."New value: +"Fetch all comments in a docket by docket ID (e.g. \"EPA-HQ-OAR-2025-0194\"). Broadest scope. Exactly one of docket_id / document_object_id / fr_document_number / comment_id is required — supplying two is rejected, not resolved by precedence."

Previous value: -"Fetch comments on one specific document by its Regulations.gov object ID (the objectId from regulations_get_docket's documents). Comments usually attach to the docket's primary (proposed-rule) document."New value: +"Fetch comments on one specific document by its Regulations.gov object ID (the objectId from regulations_get_docket's documents). Comments usually attach to the docket's primary (proposed-rule) document. Mutually exclusive with the other three targeting parameters."

Previous value: -"Convenience: fetch comments for a Federal Register document by its FR number (e.g. \"2025-14555\"). Resolves to the Regulations.gov document internally. Saves a get_document → get_docket hop."New value: +"Convenience: fetch comments for a Federal Register document by its FR number (e.g. \"2025-14555\"). Resolves to the Regulations.gov document internally. Saves a get_document → get_docket hop. Mutually exclusive with the other three targeting parameters."

Previous value: -"Point-in-time date, ISO 8601 (YYYY-MM-DD). Defaults to current. Structure mode uses this date for historical hierarchy; in search mode, a past date enables point-in-time search."New value: +"Point-in-time date, ISO 8601 (YYYY-MM-DD). Defaults to current. Structure mode uses it for the historical hierarchy. Search mode matches only the section text in effect on that day, so a past date searches the CFR as it read then; eCFR indexes 2017-01-03 onward and rejects a date past its current index date."

Previous value: -"CFR title number (1–50). Structure mode: omit to list all 50 titles, or provide to expand one title. Search mode: optional filter to restrict to one title."New value: +"CFR title number (1–50). Structure mode: omit to list all 50 titles, or provide to expand one title. Search mode: optional filter restricting matches to that title — e.g. 40 for environmental rules, 21 for food and drugs."

Previous value: -"Resolved point-in-time date (structure mode)."New value: +"Resolved point-in-time date — the hierarchy snapshot (structure mode), or the day whose section text was searched (search mode, live source only)."

Previous value: -"Section/part heading."New value: +"What the matched node is called — the section, appendix, or part heading. Distinct from cfrCite, which is where it lives."

Previous value: -"Human-readable hierarchy path."New value: +"Structural path down to the match, e.g. \"Title 40 › Chapter I › Part 51 › § 51.190\"."

Previous value: -"Section identifier, or null."New value: +"Section identifier, or null when the match is an appendix or a whole part."

Previous value: -"Provenance: the synced mirror index, or the live eCFR search fallback (search mode)."New value: +"Provenance: the synced mirror index, or the live eCFR search API (search mode)."

Added value: +{
+  "description": "What the answering corpus covers — the mirror's title coverage, or the live index and the date it was read at (search mode). Read it before concluding a query found nothing.",
+  "type": "string"
+}