clinicaltrialsgov-mcp-server

Previous value: -"Country name. E.g., \"United States\"."New value: +"Country name, e.g. \"United States\". Common synonyms rank sites as the registry spelling does: USA and US as United States, UK and England as United Kingdom, Czech Republic as Czechia, Republic of Korea as South Korea, and PR, GU, VI, AS, and MP as the US territories, which the registry files as countries."

Previous value: -"State or province, compared with the state the site files. With city also given, a site that files no state still matches; without city, only sites filing this state match."New value: +"State or province, compared with the state the site files. A US state or DC abbreviation (WA, DC) is compared as its full name when the country is the United States or a synonym for it. With city also given, a site that files no state still matches; without city, only sites filing this state match."

Previous value: -"Advanced filter using AREA[FieldName]value syntax. Examples: \"AREA[StudyType]INTERVENTIONAL\", \"AREA[EnrollmentCount]RANGE[100, 1000]\", \"AREA[Phase]PHASE2 AND AREA[StudyType]INTERVENTIONAL\", \"(AREA[Phase]PHASE3 OR AREA[Phase]PHASE4) AND AREA[StudyType]INTERVENTIONAL\". AND/OR/NOT join complete AREA[FieldName]value expressions; parentheses group them. Call clinicaltrials_get_field_definitions to find AREA[]-compatible field names. A record-field name that differs from the spelling AREA[] accepts only by case (AREA[overallstatus]) is corrected before the request, here and in the query parameters, and searchCriteria shows the expression as sent; index-only pieces and search areas are not case-corrected."New value: +"Advanced filter using AREA[FieldName]value syntax. Examples: \"AREA[StudyType]INTERVENTIONAL\", \"AREA[EnrollmentCount]RANGE[100, 1000]\", \"AREA[Phase]PHASE2 AND AREA[StudyType]INTERVENTIONAL\", \"(AREA[Phase]PHASE3 OR AREA[Phase]PHASE4) AND AREA[StudyType]INTERVENTIONAL\". AND/OR/NOT join complete AREA[FieldName]value expressions; parentheses group them. Call clinicaltrials_get_field_definitions to find AREA[]-compatible field names. A field name — a record field, an index-only piece such as NumLocations, or a search area such as ConditionSearch — that differs from the spelling AREA[] accepts only by case (AREA[overallstatus]) is corrected before the request, here and in the query parameters, and searchCriteria shows the expression as sent."

Previous value: -"Adverse events. Summary mode: timeFrame, groupCount, seriousEventCount, otherEventCount, eventGroups (id and title of each event group), plus topEvents — up to 20 events ranked by the most participants affected in any one event group, each with term, organSystem, kind, and byGroup (one { groupId, numAffected, numAtRisk } row per event group; resolve groupId against eventGroups). Counts are never pooled across groups: groups can overlap (a crossover or second-course group re-counts participants of its parent arm), so compare arms row by row. Full mode: eventGroups with descriptions and per-group totals, plus seriousEvents and otherEvents with per-event term and per-group affected/at-risk stats."New value: +"Adverse events. Summary mode: timeFrame, frequencyThreshold, groupCount, seriousEventCount, otherEventCount, eventGroups (id and title of each event group), plus topEvents — up to 20 events ranked by the most participants affected in any one event group, each with term, organSystem, kind, and byGroup (one { groupId, numAffected, numAtRisk } row per event group; resolve groupId against eventGroups). Counts are never pooled across groups: groups can overlap (a crossover or second-course group re-counts participants of its parent arm), so compare arms row by row. Full mode: frequencyThreshold, eventGroups with descriptions and per-group totals, plus seriousEvents and otherEvents with per-event term and per-group affected/at-risk stats. frequencyThreshold, in either mode, is the reporting threshold as upstream sends it: other (non-serious) events are listed only when their frequency reaches it, so an other event the study does not list may still have occurred below it. Usually a percentage (\"5\", \"0\"), occasionally text (\"any\"); absent when the study publishes none."

Previous value: -"Advanced filter using AREA[FieldName]value syntax. Examples: \"AREA[StudyType]INTERVENTIONAL\", \"AREA[EnrollmentCount]RANGE[100, 1000]\", \"AREA[Phase]PHASE2 AND AREA[StudyType]INTERVENTIONAL\", \"(AREA[Phase]PHASE3 OR AREA[Phase]PHASE4) AND AREA[StudyType]INTERVENTIONAL\". \"AREA[HasResults]true\" restricts to studies with posted results. AND/OR/NOT join complete AREA[FieldName]value expressions; parentheses group them. Call clinicaltrials_get_field_definitions to find AREA[]-compatible field names. A record-field name that differs from the spelling AREA[] accepts only by case (AREA[overallstatus]) is corrected before the request, here and in the query parameters, and searchCriteria shows the expression as sent; index-only pieces and search areas are not case-corrected."New value: +"Advanced filter using AREA[FieldName]value syntax. Examples: \"AREA[StudyType]INTERVENTIONAL\", \"AREA[EnrollmentCount]RANGE[100, 1000]\", \"AREA[Phase]PHASE2 AND AREA[StudyType]INTERVENTIONAL\", \"(AREA[Phase]PHASE3 OR AREA[Phase]PHASE4) AND AREA[StudyType]INTERVENTIONAL\". \"AREA[HasResults]true\" restricts to studies with posted results. AND/OR/NOT join complete AREA[FieldName]value expressions; parentheses group them. Call clinicaltrials_get_field_definitions to find AREA[]-compatible field names. A field name — a record field, an index-only piece such as NumLocations, or a search area such as ConditionSearch — that differs from the spelling AREA[] accepts only by case (AREA[overallstatus]) is corrected before the request, here and in the query parameters, and searchCriteria shows the expression as sent."

Previous value: -"Matching studies. By default each entry is a COMPACT index projection — nctId, briefTitle, overallStatus, phases, enrollmentCount, leadSponsor, conditions, hasResults, startDate and primaryCompletionDate (YYYY-MM or YYYY-MM-DD, as registered), and a bounded locations summary ({ total, nearest }); keys the study does not publish are omitted — mirroring the rendered result, NOT the full ~70KB record. Pass the fields parameter to receive exactly the requested leaves at full fidelity instead (e.g. all locations). Fetch a full single record with clinicaltrials_get_study_record."New value: +"Matching studies. By default each entry is a COMPACT index projection — nctId, briefTitle, overallStatus, phases, enrollmentCount, leadSponsor, conditions, hasResults, startDate and primaryCompletionDate (YYYY-MM or YYYY-MM-DD, as registered), and a bounded locations summary ({ total, nearest: { facility, city, state, country, status, distanceMi } }). nearest is the site closest to the geoFilter center, carrying distanceMi, or the lead registered site when no geoFilter is set; its status is that one site's own recruitment status, which can differ from the study's overallStatus, and is absent when the site publishes none. Keys the study does not publish are omitted — mirroring the rendered result, NOT the full ~70KB record. Pass the fields parameter to receive exactly the requested leaves at full fidelity instead (e.g. all locations). Fetch a full single record with clinicaltrials_get_study_record."

Previous value: -"Patient location as `{ country (required), state?, city? }`. Country is required; state/city narrow the match. For radius-based geographic search, use clinicaltrials_search_studies with geoFilter."New value: +"Patient location as `{ country (required), state?, city? }`. Country is required; state/city narrow the match. Every part given must hold for the same study site: country and state are compared with the site's filed country and state, while city is matched against the site's whole location text, so a site filed under a borough or neighbouring town that names the city still counts. For radius-based geographic search, use clinicaltrials_search_studies with geoFilter."

Previous value: -"State or province."New value: +"State or province, compared with the state the site files. With city also given, a site that files no state still matches; without city, only sites filing this state match."

Previous value: -"Machine-readable failure mode. Declared by this tool: `blank_value`: A conditions entry or location.country was supplied blank — empty, whitespace-only, or made only of `\"` characters, invisible format characters such as zero-width spaces, and whitespace, since `\"` is stripped before the query is built — or conditions was an empty list. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `blank_value`: A conditions entry or location.country was supplied blank — empty, whitespace-only, or made only of `\"` characters, invisible format characters such as zero-width spaces, and whitespace, since `\"` is stripped before the query is built — or conditions was an empty list. `field_invalid`: A conditions entry carries an AREA[] expression naming a field ClinicalTrials.gov does not recognize or cannot search by value. `query_parse_error`: A conditions entry uses syntax the upstream Essie parser rejects — typically an unmatched `(` or `)`, or a `[` or `]` outside an AREA[…] expression. `request_too_long`: The conditions list or location makes the request URL longer than ClinicalTrials.gov accepts — several hundred conditions in one call. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler."

Previous value: -[
-  "blank_value",
-  "rate_limited"
-]New value: +[
+  "blank_value",
+  "field_invalid",
+  "query_parse_error",
+  "request_too_long",
+  "rate_limited"
+]

Previous value: -"The exact queryLocn string sent upstream: city/state/country AND-joined inside SEARCH[Location](…) so every part must match the same site, each part quoted unless it is a single run of letters and digits (Toronto stays bare; \"United States\", \"Winston-Salem\", and \"L'Aquila\" are quoted), with any embedded double quote stripped and any backslash in a quoted part doubled. Pass as locationQuery to clinicaltrials_search_studies to reproduce the location filter beyond the maxResults cap."New value: +"The exact queryLocn string sent upstream: the parts AND-joined inside SEARCH[Location](…) so every part must match the same site. The city is a search term, quoted unless it is a single run of letters and digits (Toronto stays bare; \"Winston-Salem\" and \"L'Aquila\" are quoted); the state is AREA[LocationState]\"…\", ORed with AREA[LocationState]MISSING when a city is given; the country is AREA[LocationCountry]\"…\", ORed with the same spelling without diacritics when it carries any (México also tries Mexico). Any embedded double quote is stripped and any backslash in a quoted value doubled. Pass as locationQuery to clinicaltrials_search_studies to reproduce the location filter beyond the maxResults cap."

Previous value: -"drill mode only. Only return indexed (searchable) fields. Default: false."New value: +"drill mode only. Also list index-only pieces (search-index fields such as StudyFirstPostYear) alongside the record fields. Default: false."

Previous value: -"Machine-readable failure mode. Declared by this tool: `blank_value`: A parameter was supplied with a blank, whitespace-only, or empty-list value. `field_invalid`: A requested field name is not a valid PascalCase piece name. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `blank_value`: A parameter was supplied with a blank, whitespace-only, or empty-list value. `field_invalid`: A requested field name is not a valid PascalCase piece name. `request_too_long`: The fields list makes the request URL longer than ClinicalTrials.gov accepts — a few hundred piece names in one call. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler."

Previous value: -[
-  "blank_value",
-  "field_invalid",
-  "rate_limited"
-]New value: +[
+  "blank_value",
+  "field_invalid",
+  "request_too_long",
+  "rate_limited"
+]

Previous value: -"Advanced filter using AREA[FieldName]value syntax. Examples: \"AREA[StudyType]INTERVENTIONAL\", \"AREA[EnrollmentCount]RANGE[100, 1000]\", \"AREA[Phase]PHASE2 AND AREA[StudyType]INTERVENTIONAL\", \"(AREA[Phase]PHASE3 OR AREA[Phase]PHASE4) AND AREA[StudyType]INTERVENTIONAL\". AND/OR/NOT join complete AREA[FieldName]value expressions; parentheses group them. Call clinicaltrials_get_field_definitions to find AREA[]-compatible field names."New value: +"Advanced filter using AREA[FieldName]value syntax. Examples: \"AREA[StudyType]INTERVENTIONAL\", \"AREA[EnrollmentCount]RANGE[100, 1000]\", \"AREA[Phase]PHASE2 AND AREA[StudyType]INTERVENTIONAL\", \"(AREA[Phase]PHASE3 OR AREA[Phase]PHASE4) AND AREA[StudyType]INTERVENTIONAL\". AND/OR/NOT join complete AREA[FieldName]value expressions; parentheses group them. Call clinicaltrials_get_field_definitions to find AREA[]-compatible field names. A record-field name that differs from the spelling AREA[] accepts only by case (AREA[overallstatus]) is corrected before the request, here and in the query parameters, and searchCriteria shows the expression as sent; index-only pieces and search areas are not case-corrected."

Previous value: -"Machine-readable failure mode. Declared by this tool: `blank_value`: A parameter was supplied with a blank, whitespace-only, or empty-list value. A phaseFilter entry of only quotes or invisible format characters (zero-width space) is blank. `field_invalid`: A field name in the advanced filter or AREA[] expression is invalid (often a module name instead of a piece name). `enum_invalid`: A phaseFilter entry resolves to none of the six phase values, or statusFilter or an AREA[] expression carries a value ClinicalTrials.gov does not accept. `query_parse_error`: A free-text query or advancedFilter expression uses syntax the upstream Essie parser rejects — typically a `[` or `]` outside an AREA[…] / RANGE[…] expression, an unmatched `(` / `)`, or an unterminated quote in a query/conditionQuery/etc. value. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `blank_value`: A parameter was supplied with a blank, whitespace-only, or empty-list value. A phaseFilter entry of only quotes or invisible format characters (zero-width space) is blank. `field_invalid`: An AREA[] expression in advancedFilter or a query parameter names a field ClinicalTrials.gov does not recognize or cannot search by value — often a module or group such as LeadSponsor instead of a leaf piece such as LeadSponsorName. `enum_invalid`: A phaseFilter entry resolves to none of the six phase values, or statusFilter or an AREA[] expression carries a value ClinicalTrials.gov does not accept. `query_parse_error`: A free-text query or advancedFilter expression uses syntax the upstream Essie parser rejects — typically a `[` or `]` outside an AREA[…] / RANGE[…] expression, an unmatched `(` / `)`, or an unterminated quote in a query/conditionQuery/etc. value. `request_too_long`: The request URL runs past the length ClinicalTrials.gov accepts — typically a very long free-text query or advancedFilter expression. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler."

Previous value: -[
-  "blank_value",
-  "field_invalid",
-  "enum_invalid",
-  "query_parse_error",
-  "rate_limited"
-]New value: +[
+  "blank_value",
+  "field_invalid",
+  "enum_invalid",
+  "query_parse_error",
+  "request_too_long",
+  "rate_limited"
+]

Previous value: -"Compact counts of posted results, present when hasResults is true. The full resultsSection is intentionally omitted from this record-level tool — fetch it via clinicaltrials_get_study_results or the clinicaltrials://{nctId} resource."New value: +"Compact counts of posted results, present when hasResults is true. The full resultsSection is intentionally omitted from this record-level tool — fetch it via clinicaltrials_get_study_results."

Previous value: -"Advanced filter using AREA[FieldName]value syntax. Examples: \"AREA[StudyType]INTERVENTIONAL\", \"AREA[EnrollmentCount]RANGE[100, 1000]\", \"AREA[Phase]PHASE2 AND AREA[StudyType]INTERVENTIONAL\", \"(AREA[Phase]PHASE3 OR AREA[Phase]PHASE4) AND AREA[StudyType]INTERVENTIONAL\". \"AREA[HasResults]true\" restricts to studies with posted results. AND/OR/NOT join complete AREA[FieldName]value expressions; parentheses group them. Call clinicaltrials_get_field_definitions to find AREA[]-compatible field names."New value: +"Advanced filter using AREA[FieldName]value syntax. Examples: \"AREA[StudyType]INTERVENTIONAL\", \"AREA[EnrollmentCount]RANGE[100, 1000]\", \"AREA[Phase]PHASE2 AND AREA[StudyType]INTERVENTIONAL\", \"(AREA[Phase]PHASE3 OR AREA[Phase]PHASE4) AND AREA[StudyType]INTERVENTIONAL\". \"AREA[HasResults]true\" restricts to studies with posted results. AND/OR/NOT join complete AREA[FieldName]value expressions; parentheses group them. Call clinicaltrials_get_field_definitions to find AREA[]-compatible field names. A record-field name that differs from the spelling AREA[] accepts only by case (AREA[overallstatus]) is corrected before the request, here and in the query parameters, and searchCriteria shows the expression as sent; index-only pieces and search areas are not case-corrected."

Previous value: -[
-  {
-    "description": "A single NCT ID.",
-    "pattern": "^NCT\\d{8}$",
-    "type": "string"
-  },
-  {
-    "description": "Multiple NCT IDs (OR).",
-    "items": {
-      "pattern": "^NCT\\d{8}$",
-      "type": "string"
-    },
-    "type": "array"
-  }
-]New value: +[
+  {
+    "description": "A single NCT ID.",
+    "pattern": "^NCT\\d{8}$",
+    "type": "string"
+  },
+  {
+    "description": "Multiple NCT IDs (OR), at most 1000 entries counting repeats.",
+    "items": {
+      "pattern": "^NCT\\d{8}$",
+      "type": "string"
+    },
+    "maxItems": 1000,
+    "type": "array"
+  }
+]

Previous value: -"Filter to specific NCT IDs for batch lookups. Omit to search every study — an empty list is rejected, not treated as \"no filter\". Supplying this lifts the default unknown-enrollment exclusion, so an ID you name is never filtered out of its own lookup."New value: +"Filter to specific NCT IDs for batch lookups. Omit to search every study — an empty list is rejected, not treated as \"no filter\". Repeated IDs collapse to one, first occurrence kept. One request carries as many leading IDs as fit ClinicalTrials.gov's URL length limit beside the other parameters — about 560 when nothing else is set, fewer beside long queries or field lists — and the rest come back unqueried in deferredNctIds, in order, for a follow-up call; every page of a walk queries the same IDs. A list over 1000 entries, repeats included, is rejected. Supplying this lifts the default unknown-enrollment exclusion, so an ID you name is never filtered out of its own lookup."

Added value: +{
+  "description": "IDs from nctIds that did not fit in one ClinicalTrials.gov request beside the other parameters, deduplicated, in first-occurrence order. Not queried — studies and totalCount cover only the IDs that went out; pass these as nctIds in a follow-up call with the same criteria. Every page of a walk defers the same IDs. Absent when every requested ID was queried.",
+  "items": {
+    "type": "string"
+  },
+  "type": "array"
+}

Previous value: -"Machine-readable failure mode. Declared by this tool: `blank_value`: A parameter was supplied with a blank, whitespace-only, or empty-list value. A fields or phaseFilter entry of only invisible format characters (zero-width space) is blank, and so is a phaseFilter entry of only quotes. `ids_not_found`: One or more NCT IDs in the nctIds filter are not present at ClinicalTrials.gov. `field_invalid`: A field name in the fields parameter or AREA[] expression is invalid (often a module name instead of a piece name). `enum_invalid`: A phaseFilter entry resolves to none of the six phase values, or statusFilter or an AREA[] expression carries a value ClinicalTrials.gov does not accept. `query_parse_error`: A free-text query or advancedFilter expression uses syntax the upstream Essie parser rejects — typically a `[` or `]` outside an AREA[…] / RANGE[…] expression, an unmatched `(` / `)`, or an unterminated quote in a query/conditionQuery/etc. value. `geo_invalid`: geoFilter is not a well-formed distance(lat,lon,radius) expression. `sort_invalid`: sort is not FieldName:asc / FieldName:desc, or names more than 2 fields. `page_token_invalid`: ClinicalTrials.gov rejected pageToken as malformed (not a token it issued), or as unresumable (issued before a data refresh, or altered after issue). `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `blank_value`: A parameter was supplied with a blank, whitespace-only, or empty-list value. A fields or phaseFilter entry of only invisible format characters (zero-width space) is blank, and so is a phaseFilter entry of only quotes. `ids_not_found`: One or more NCT IDs in the nctIds filter are not present at ClinicalTrials.gov. `field_invalid`: A name in the fields parameter is not a field, or an AREA[] expression names a field ClinicalTrials.gov does not recognize or cannot search by value — often a module or group such as LeadSponsor instead of a leaf piece such as LeadSponsorName. `enum_invalid`: A phaseFilter entry resolves to none of the six phase values, or statusFilter or an AREA[] expression carries a value ClinicalTrials.gov does not accept. `query_parse_error`: A free-text query or advancedFilter expression uses syntax the upstream Essie parser rejects — typically a `[` or `]` outside an AREA[…] / RANGE[…] expression, an unmatched `(` / `)`, or an unterminated quote in a query/conditionQuery/etc. value. `geo_invalid`: geoFilter is not a well-formed distance(lat,lon,radius) expression. `sort_invalid`: sort is not FieldName:asc / FieldName:desc, or names more than 2 fields. `page_token_invalid`: ClinicalTrials.gov rejected pageToken as malformed (not a token it issued), or as unresumable (issued before a data refresh, or altered after issue). `request_too_long`: The request URL runs past the length ClinicalTrials.gov accepts — long free-text queries, advancedFilter, or fields — or the other parameters leave no room for even one nctIds entry. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler."

Previous value: -[
-  "blank_value",
-  "ids_not_found",
-  "field_invalid",
-  "enum_invalid",
-  "query_parse_error",
-  "geo_invalid",
-  "sort_invalid",
-  "page_token_invalid",
-  "rate_limited"
-]New value: +[
+  "blank_value",
+  "ids_not_found",
+  "field_invalid",
+  "enum_invalid",
+  "query_parse_error",
+  "geo_invalid",
+  "sort_invalid",
+  "page_token_invalid",
+  "request_too_long",
+  "rate_limited"
+]

Previous value: -"Patient age in years."New value: +"Patient age as a whole number in ageUnit (years unless ageUnit says otherwise)."

Added value: +{
+  "description": "Unit age is given in: years (default), months, weeks, or days; case and singular forms are accepted. Use a smaller unit for an infant or young child whose eligibility window is narrower than a year — age 7 with ageUnit \"months\" matches a study registered for 6 Months to 8 Months, which no whole number of years reaches. ClinicalTrials.gov compares ages across units, so the unit only sets how precisely age is stated.",
+  "enum": [
+    "years",
+    "months",
+    "weeks",
+    "days"
+  ],
+  "type": "string"
+}

Previous value: -"Medical conditions or diagnoses, e.g. [\"Type 2 Diabetes\", \"Hypertension\"]. Each entry is matched as a condition (multi-word entries match as a phrase); multiple entries are combined with OR, so studies for any listed condition qualify. Returned studies are re-ranked so those whose own condition list names a requested condition rank above tangential matches the upstream fuzzy search pulls in via the MeSH umbrella."New value: +"Medical conditions or diagnoses, e.g. [\"Type 2 Diabetes\", \"Hypertension\"]. Each entry is matched as a condition: an entry containing whitespace is quoted and matches as a phrase, and any other entry is sent as written, punctuation included (double quotes are stripped from every entry); multiple entries are combined with OR, so studies for any listed condition qualify. Returned studies are re-ranked so those whose own condition list names a requested condition rank above tangential matches the upstream fuzzy search pulls in via the MeSH umbrella."

Previous value: -"Cap on the sites returned per candidate. Each candidate keeps only the sites matching the requested location at the narrowest level that matched (city, else state, else country), capped at this many; the rest of the study's registered sites are omitted. The cap governs those matched sites — when none of them is recruiting, one recruiting site is added on top of it (the nearest to any matched site, measured before this cap, when coordinates allow — in the requested country whenever a site there recruits), so a candidate can carry one site more than this. Raise it to see more nearby sites, or fetch the complete site list with clinicaltrials_get_study_record. Each candidate reports totalLocations / matchedLocations / locationsTruncated / nearestRecruitingSiteAdded in locationSummary only when the bound actually dropped sites."New value: +"Cap on the sites returned per candidate. Each candidate keeps only the sites matching the requested location at the narrowest level that matched (city, else state, else country), capped at this many; the rest of the study's registered sites are omitted. The cap governs those matched sites — when none of them is recruiting, one recruiting site is added on top of it (the nearest to any matched site, measured before this cap, when coordinates allow — in the requested country whenever a site there recruits), so a candidate can carry one site more than this. Raise it to see more nearby sites — there is no upper bound, and a limit past the matched sites returns all of them — or fetch the complete site list with clinicaltrials_get_study_record. Each candidate reports totalLocations / matchedLocations / locationsTruncated / nearestRecruitingSiteAdded in locationSummary only when the bound actually dropped sites."

Previous value: -500New value: +9007199254740991

Previous value: -"Maximum results to return."New value: +"Maximum candidates to return, 1–1000. Each call returns at most 50; a larger value returns 50, reported in truncated/shown/cap when more studies match, and the searchCriteria replay through clinicaltrials_search_studies pages the rest."

Previous value: -50New value: +1000

Added value: +{
+  "description": "The tool's per-call cap, served in place of the requested maxResults when truncated is true.",
+  "exclusiveMinimum": 0,
+  "maximum": 9007199254740991,
+  "type": "integer"
+}

Previous value: -"When no studies matched, recovery guidance that identifies which filter stage collapsed and suggests how to broaden. When studies are returned, one caveat for the whole response: candidates were matched on demographics, location, recruitment status, and a fuzzy condition search, not on inclusion/exclusion criteria."New value: +"When no studies matched, recovery guidance that identifies which filter stage collapsed and suggests how to broaden. When studies are returned, one caveat for the whole response: candidates were matched on demographics, location, recruitment status, and a fuzzy condition search, not on inclusion/exclusion criteria. When maxResults was above the tool's per-call cap and more studies match, a sentence follows stating the requested, served, and total counts and pointing at the searchCriteria replay."

Previous value: -"Patient age."New value: +"Patient age, in ageUnit when present, else in years."

Added value: +{
+  "description": "The unit age was given in. Present only for months, weeks, or days; absent means years.",
+  "enum": [
+    "years",
+    "months",
+    "weeks",
+    "days"
+  ],
+  "type": "string"
+}

Previous value: -"The exact queryLocn string sent upstream (city/state/country, multi-word components quoted, AND-joined). Pass as locationQuery to clinicaltrials_search_studies to reproduce the location filter beyond the maxResults cap."New value: +"The exact queryLocn string sent upstream: city/state/country AND-joined inside SEARCH[Location](…) so every part must match the same site, each part quoted unless it is a single run of letters and digits (Toronto stays bare; \"United States\", \"Winston-Salem\", and \"L'Aquila\" are quoted), with any embedded double quote stripped and any backslash in a quoted part doubled. Pass as locationQuery to clinicaltrials_search_studies to reproduce the location filter beyond the maxResults cap."

Added value: +{
+  "description": "Candidates returned when truncated is true.",
+  "maximum": 9007199254740991,
+  "minimum": 0,
+  "type": "integer"
+}

Added value: +{
+  "description": "True when maxResults was above the tool's per-call cap and more studies match than were returned. Absent otherwise.",
+  "type": "boolean"
+}

Previous value: -"search mode only. Maximum results to return. Default: 20."New value: +"search mode only. Maximum results to return. Default: 20. A value at or past the match count returns every match."

Previous value: -100New value: +9007199254740991

Previous value: -"Its length in characters."New value: +"Full length of the recorded value in characters, even when truncated."

Added value: +{
+  "const": true,
+  "description": "True when value is a preview of at most 2,000 characters; absent when value is whole. The notice names the clinicaltrials_search_studies call that returns the full text.",
+  "type": "boolean"
+}

Previous value: -"The longest recorded value."New value: +"The longest recorded value — when truncated is true, only a prefix of at most 2,000 characters (1,999 when the cut would split a surrogate pair)."

Previous value: -"Number of distinct values."New value: +"Number of distinct values, as ClinicalTrials.gov reports it. Free-text STRING fields it does not count (DetailedDescription, EligibilityCriteria) report 0 here alongside uniqueValuesCounted: false — that 0 is not a count. A 0 without the flag means no recorded values."

Added value: +{
+  "const": false,
+  "description": "False when ClinicalTrials.gov did not count distinct values for this field, so the uniqueValuesCount of 0 is not a real count — the field has recorded values (see longest) but no topValues. Absent otherwise.",
+  "type": "boolean"
+}

Added value: +{
+  "description": "Present when a longest value was cut to a preview — names, for each such field, the clinicaltrials_search_studies arguments that return its full text.",
+  "type": "string"
+}

Previous value: -"Optional cap on the number of locations returned. Omit for no cap (full upstream list). Pairs naturally with nearLocation for narrowing a large multi-site trial. Original total preserved in filtersApplied.totalLocations only when the cap trims the list."New value: +"Optional cap on the number of locations returned. Omit for no cap (full upstream list); a value at or past the list length also returns every location. Pairs naturally with nearLocation for narrowing a large multi-site trial. Original total preserved in filtersApplied.totalLocations only when the cap trims the list."

Previous value: -500New value: +9007199254740991

Previous value: -"Radius in miles. Default 50."New value: +"Radius in miles, at least 1. Default 50. A radius past the farthest site keeps every site with published coordinates."

Removed value: -500

Previous value: -"Optional cap on the number of secondary and other outcomes returned. Omit for no cap (full upstream lists). Primary outcomes are never capped. Original totals preserved in filtersApplied.totalSecondaryOutcomes / totalOtherOutcomes only when the cap trims a list."New value: +"Optional cap on the number of secondary and other outcomes returned. Omit for no cap (full upstream lists); a value at or past a list length also returns that whole list. Primary outcomes are never capped. Original totals preserved in filtersApplied.totalSecondaryOutcomes / totalOtherOutcomes only when the cap trims a list."

Previous value: -100New value: +9007199254740991

Previous value: -"Optional cap on the number of references returned. Omit for no cap (full upstream list). Original total preserved in filtersApplied.totalReferences only when the cap trims the list. seeAlsoLinks are never capped."New value: +"Optional cap on the number of references returned. Omit for no cap (full upstream list); a value at or past the list length also returns every reference. Original total preserved in filtersApplied.totalReferences only when the cap trims the list. seeAlsoLinks are never capped."

Previous value: -100New value: +9007199254740991

Previous value: -"Optional cap on the number of serious and other adverse events returned per study, applied to each list separately in upstream order. Omit for no cap (every event). Applies to full mode only — summary mode already ranks the top 20 by the most participants affected in any one event group. Event groups are never capped. Upstream totals preserved in filtersApplied.totalSeriousEvents / totalOtherEvents only when the cap trims a list."New value: +"Optional cap on the number of serious and other adverse events returned per study, applied to each list separately in upstream order. Omit for no cap (every event); a limit at or past a list’s length returns that whole list. Applies to full mode only — summary mode already ranks the top 20 by the most participants affected in any one event group. Event groups are never capped. Upstream totals preserved in filtersApplied.totalSeriousEvents / totalOtherEvents only when the cap trims a list."

Previous value: -500New value: +9007199254740991

Previous value: -[
-  {
-    "description": "A single NCT ID.",
-    "pattern": "^NCT\\d{8}$",
-    "type": "string"
-  },
-  {
-    "description": "Multiple NCT IDs (max 20).",
-    "items": {
-      "pattern": "^NCT\\d{8}$",
-      "type": "string"
-    },
-    "maxItems": 20,
-    "type": "array"
-  }
-]New value: +[
+  {
+    "description": "A single NCT ID.",
+    "pattern": "^NCT\\d{8}$",
+    "type": "string"
+  },
+  {
+    "description": "Multiple NCT IDs, at most 500 entries counting repeats.",
+    "items": {
+      "pattern": "^NCT\\d{8}$",
+      "type": "string"
+    },
+    "maxItems": 500,
+    "type": "array"
+  }
+]

Previous value: -"One or more NCT IDs (max 20) — an empty list is rejected, and a repeated ID collapses to one results entry in first-occurrence order. E.g., \"NCT12345678\" or [\"NCT12345678\", \"NCT87654321\"]. Use summary=true for large batches to avoid large payloads."New value: +"One or more NCT IDs — an empty list is rejected, and a repeated ID collapses to one results entry in first-occurrence order. A call fetches the first 20 distinct IDs; any further distinct IDs come back unfetched in deferredNctIds, in first-occurrence order, for a follow-up call. A list over 500 entries, repeats included, is rejected. E.g., \"NCT12345678\" or [\"NCT12345678\", \"NCT87654321\"]. Use summary=true for large batches to avoid large payloads."

Previous value: -"Optional cap on the number of outcome measures returned per study, taken in the order ClinicalTrials.gov publishes them. Omit for no cap (every measure). Applies in both modes: each surviving measure keeps its complete groups/classes/measurements/analyses tree in full mode, or its whole summary projection with summary: true. Upstream total preserved in filtersApplied.totalOutcomes only when the cap trims the list."New value: +"Optional cap on the number of outcome measures returned per study, taken in the order ClinicalTrials.gov publishes them. Omit for no cap (every measure); a limit at or past the list length returns the whole list. Applies in both modes: each surviving measure keeps its complete groups/classes/measurements/analyses tree in full mode, or its whole summary projection with summary: true. Upstream total preserved in filtersApplied.totalOutcomes only when the cap trims the list."

Previous value: -100New value: +9007199254740991

Added value: +{
+  "description": "Requested NCT IDs past the per-call cap of 20 distinct IDs, normalized and deduplicated, in first-occurrence order. Not fetched — pass them as nctIds in a follow-up call. Absent when every requested ID was processed.",
+  "items": {
+    "type": "string"
+  },
+  "type": "array"
+}

Previous value: -"Results per page, 1–200."New value: +"Results per page, 1–1000. A value above this server's per-page cap (200 unless the operator changed it) returns a page at the cap, reported in truncated/shown/cap with nextPageToken to continue."

Previous value: -200New value: +1000

Added value: +{
+  "description": "The server's per-page cap, served in place of the requested pageSize when truncated is true.",
+  "exclusiveMinimum": 0,
+  "maximum": 9007199254740991,
+  "type": "integer"
+}

Previous value: -"Recovery guidance when no studies matched — echoes the constraint and suggests how to broaden, and names nctIds as part of the unmatched criteria when an ID list was supplied. Absent on pages with results, and on an exhausted continuation page, where the cohort already matched and there is nothing to broaden."New value: +"Recovery guidance when no studies matched — echoes the constraint and suggests how to broaden, and names nctIds as part of the unmatched criteria when an ID list was supplied. On a page cut to the server's per-page cap, states the requested and served page sizes and points at nextPageToken. Absent on other pages with results, and on an exhausted continuation page, where the cohort already matched and there is nothing to broaden."

Added value: +{
+  "description": "Studies on this page when truncated is true.",
+  "maximum": 9007199254740991,
+  "minimum": 0,
+  "type": "integer"
+}

Added value: +{
+  "description": "True when pageSize was above the server's per-page cap and this page filled to the cap with a nextPageToken. Without a total to check against (countTotal: false, or a continuation page), that next page can be empty. Absent otherwise.",
+  "type": "boolean"
+}

Previous value: -"Machine-readable failure mode. Declared by this tool: `blank_value`: A parameter was supplied with a blank, whitespace-only, or empty-list value. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `blank_value`: A conditions entry or location.country was supplied blank — empty, whitespace-only, or made only of `\"` characters, invisible format characters such as zero-width spaces, and whitespace, since `\"` is stripped before the query is built — or conditions was an empty list. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler."

Previous value: -"Recovery guidance when no studies matched — identifies which filter stage collapsed and suggests how to broaden. Absent when results are returned."New value: +"When no studies matched, recovery guidance that identifies which filter stage collapsed and suggests how to broaden. When studies are returned, one caveat for the whole response: candidates were matched on demographics, location, recruitment status, and a fuzzy condition search, not on inclusion/exclusion criteria."

Previous value: -"Matching studies with eligibility and location fields. Each candidate's protocolSection.contactsLocationsModule.locations is BOUNDED to the sites matching the requested location (capped at locationLimit) plus, when none of those is recruiting, one added recruiting site — not the study's full registered site list. The added site is the one nearest any matched site by published coordinates, taken from the requested country whenever a site there recruits, and carries distanceMi (miles to that nearest matched site); when the matched or recruiting sites publish no coordinates it is the first in match order and carries no distanceMi. A candidate whose sites were bounded also carries a top-level locationSummary object — { totalLocations, matchedLocations, locationsTruncated, nearestRecruitingSiteAdded?, retrieveFullStudyWith } — absent when nothing was dropped; nearestRecruitingSiteAdded is present only when that extra site was added (the key keeps its name in the match-order fallback). Fetch a study's complete record and site list with clinicaltrials_get_study_record."New value: +"Candidate studies with their demographic limits (age, sex, healthy volunteers), contacts, and location fields — matched on age, sex, location, recruitment status, and the fuzzy condition search; inclusion/exclusion criteria are not checked and are not in these records, so review each candidate with clinicaltrials_get_study_record. Each candidate's protocolSection.contactsLocationsModule.locations is BOUNDED to the sites matching the requested location (capped at locationLimit) plus, when none of those is recruiting, one added recruiting site — not the study's full registered site list. The added site is the one nearest any matched site by published coordinates, taken from the requested country whenever a site there recruits, and carries distanceMi (miles to that nearest matched site); when the matched or recruiting sites publish no coordinates it is the first in match order and carries no distanceMi. A candidate whose sites were bounded also carries a top-level locationSummary object — { totalLocations, matchedLocations, locationsTruncated, nearestRecruitingSiteAdded?, retrieveFullStudyWith } — absent when nothing was dropped; nearestRecruitingSiteAdded is present only when that extra site was added (the key keeps its name in the match-order fallback). Fetch a study's complete record and site list with clinicaltrials_get_study_record."

Previous value: -"PascalCase field name(s) to get value statistics for — an empty list is rejected, not treated as \"every field\". Examples: OverallStatus, Phase, StudyType, Sex, LeadSponsorClass. Use clinicaltrials_get_field_definitions with a query to find more field names."New value: +"PascalCase field name(s) to get value statistics for — an empty list is rejected, not treated as \"every field\". A comma- or pipe-joined string (\"Phase,StudyType\") is split into separate names. Examples: OverallStatus, Phase, StudyType, Sex, LeadSponsorClass. Use clinicaltrials_get_field_definitions with a query to find more field names."

Previous value: -"Filter by trial phase. Omit to count all phases — an empty list is rejected, not treated as \"no filter\". Values: EARLY_PHASE1, PHASE1, PHASE2, PHASE3, PHASE4, NA."New value: +"Filter by trial phase. Omit to count all phases — an empty list is rejected, not treated as \"no filter\". Values: EARLY_PHASE1, PHASE1, PHASE2, PHASE3, PHASE4, NA. Case and spacing variants (\"Phase 3\", \"early phase 1\", \"Not Applicable\") are accepted, and a list or a comma- or pipe-joined string matches any of the phases. Each entry must name a phase — put search expressions (OR, NOT, AREA[…]) in advancedFilter."

Previous value: -"Machine-readable failure mode. Declared by this tool: `blank_value`: A parameter was supplied with a blank, whitespace-only, or empty-list value. `field_invalid`: A field name in the advanced filter or AREA[] expression is invalid (often a module name instead of a piece name). `enum_invalid`: statusFilter or phaseFilter contains a value ClinicalTrials.gov does not accept. `query_parse_error`: A free-text query or advancedFilter expression uses syntax the upstream Essie parser rejects — typically a `[` or `]` outside an AREA[…] / RANGE[…] expression, an unmatched `(` / `)`, or an unterminated quote in a query/conditionQuery/etc. value. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `blank_value`: A parameter was supplied with a blank, whitespace-only, or empty-list value. A phaseFilter entry of only quotes or invisible format characters (zero-width space) is blank. `field_invalid`: A field name in the advanced filter or AREA[] expression is invalid (often a module name instead of a piece name). `enum_invalid`: A phaseFilter entry resolves to none of the six phase values, or statusFilter or an AREA[] expression carries a value ClinicalTrials.gov does not accept. `query_parse_error`: A free-text query or advancedFilter expression uses syntax the upstream Essie parser rejects — typically a `[` or `]` outside an AREA[…] / RANGE[…] expression, an unmatched `(` / `)`, or an unterminated quote in a query/conditionQuery/etc. value. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler."

Previous value: -"Optional cap on the number of outcome measures returned per study, taken in the order ClinicalTrials.gov publishes them. Omit for no cap (every measure). Applies to full mode only — summary mode is already condensed. Each surviving measure keeps its complete groups/classes/measurements/analyses tree. Upstream total preserved in filtersApplied.totalOutcomes only when the cap trims the list."New value: +"Optional cap on the number of outcome measures returned per study, taken in the order ClinicalTrials.gov publishes them. Omit for no cap (every measure). Applies in both modes: each surviving measure keeps its complete groups/classes/measurements/analyses tree in full mode, or its whole summary projection with summary: true. Upstream total preserved in filtersApplied.totalOutcomes only when the cap trims the list."

Previous value: -"Optional index of the first outcome measure to return, in the order ClinicalTrials.gov publishes them. Omit or 0 to start at the first. Pair with outcomeLimit to page a long list: each response reports filtersApplied.nextOutcomeOffset for the study, and the list is exhausted when that field is absent. Applied to every study in the call. An offset at or past the end returns an empty list with filtersApplied.totalOutcomes stating the upstream length, not an error. Rejected with summary: true or when sections excludes outcomes."New value: +"Optional index of the first outcome measure to return, in the order ClinicalTrials.gov publishes them. Omit or 0 to start at the first. Pair with outcomeLimit to page a long list: each response reports filtersApplied.nextOutcomeOffset for the study, and the list is exhausted when that field is absent. Applied to every study in the call. An offset at or past the end returns an empty list with filtersApplied.totalOutcomes stating the upstream length, not an error. Works in summary mode too, paging the summarized measures. Rejected when sections excludes outcomes."

Previous value: -"Return condensed summaries instead of full data. Full mode renders every row and field on both output channels, so a large results set can exceed 500KB per study; summary mode typically cuts that to a few KB, scaling with the measure count rather than to a fixed ceiling. An outcome summary keeps the title, type, timeframe, paramType, dispersionType, unit, group/class counts, per-group denominators, one statistical analysis, and a top-line projection of a single class/category cell — labelled with the class and category titles it came from and a count of the siblings it omits. The measurements outside that cell and the remaining analyses are dropped; re-run with summary=false to reach them. For a middle ground, keep full mode and cap the two lists that carry the bulk with outcomeLimit / adverseEventLimit."New value: +"Return condensed summaries instead of full data. Full mode renders every row and field on both output channels, so a large results set can exceed 500KB per study; summary mode typically cuts that to a few KB, scaling with the measure count rather than to a fixed ceiling. An outcome summary keeps the title, type, timeframe, paramType, dispersionType, unit, group/class/analysis counts, per-group denominators, a top-line projection of a single class/category cell — labelled with the class and category titles it came from, that class’s own denominators, and a count of the siblings it omits — and the first statistical analysis with its group description and compared groups named by title. The measurements outside that cell and the remaining analyses are dropped; re-run with summary=false to reach them. outcomeLimit / outcomeOffset page the summarized outcome list as they page full mode; the adverse-event bounds do not apply here, since topEvents ranks the whole event list. For a middle ground, keep full mode and cap the two lists that carry the bulk with outcomeLimit / adverseEventLimit."

Added value: +[
+  "nctIds"
+]

Previous value: -"Machine-readable failure mode. Declared by this tool: `blank_value`: A parameter was supplied with a blank, whitespace-only, or empty-list value. `offset_not_applicable`: An offset was supplied for a list this call does not return — summary mode returns a condensed projection rather than a bounded window, or the sections filter excludes the offset’s own section. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `blank_value`: A parameter was supplied with a blank, whitespace-only, or empty-list value. `offset_not_applicable`: An offset was supplied for a list this call does not return as a window — an adverse-event offset in summary mode, which ranks the whole event list into topEvents, or any offset whose own section the sections filter excludes. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler."

Previous value: -"What the outcomeLimit / adverseEventLimit caps and the outcomeOffset / seriousEventOffset / otherEventOffset offsets trimmed on this study, plus the next offset for each list left short. Present only when a bound actually reduced a list — a window that started at zero and reached the end trimmed nothing. Absent means the payload is the complete upstream set for the requested sections. Offsets apply uniformly to every study in the call, so continuation is reported per study: each exhausts its lists at a different index."New value: +"What the outcomeLimit / adverseEventLimit caps and the outcomeOffset / seriousEventOffset / otherEventOffset offsets trimmed on this study, plus the next offset for each list left short. In summary mode only the outcome bounds apply. Present only when a bound actually reduced a list — a window that started at zero and reached the end trimmed nothing. Absent means the payload is the complete upstream set for the requested sections. Offsets apply uniformly to every study in the call, so continuation is reported per study: each exhausts its lists at a different index."

Previous value: -"Outcome measures with per-group statistics. Summary mode (compact): type, title, timeFrame, paramType, dispersionType, unitOfMeasure, group/class counts, denoms (per-group denominators keyed by group title), topStats (the per-group cells of one class/category — each carrying the upstream value verbatim, including an NA/NR sentinel, plus spread, lowerLimit/upperLimit, and the record’s own comment when present), topStatsFrom (classTitle / categoryTitle naming where that cell came from, with omittedClasses / omittedCategories counts and a note pointing at summary=false when siblings were dropped), and topAnalysis (statisticalMethod, pValue, paramType/Value, ciPctValue/Lower/Upper, nonInferiorityType, groupIds — lifted from analyses[0]) when present. Full mode (default): adds raw groups, classes, categories, measurements, and analyses arrays."New value: +"Outcome measures with per-group statistics. Summary mode (compact): type, title, timeFrame, paramType, dispersionType, unitOfMeasure, groupCount / classCount, analysisCount (how many analyses the measure carries, when it has any), denoms (the whole measure’s per-group denominators keyed by group title), topStats (the per-group cells of one class/category — each carrying the upstream value verbatim, including an NA/NR sentinel, plus spread, lowerLimit/upperLimit, and the record’s own comment when present), topStatsFrom (classTitle / categoryTitle naming where that cell came from, classDenoms — that class’s own denominators, shaped like denoms, when upstream publishes them — omittedClasses / omittedCategories counts, and a note pointing at summary=false when siblings were dropped), and topAnalysis (statisticalMethod, pValue, paramType/Value, ciPctValue/Lower/Upper, nonInferiorityType, groupDescription naming the subgroup or comparison, groupIds, and groups — the compared groups’ titles in groupIds order — lifted from analyses[0]) when present. Every summary field is resolved per measure. Full mode (default): adds raw groups, classes, categories, measurements, and analyses arrays."

Previous value: -"PascalCase leaf names to return; strongly recommended since full records are ~70KB. Omit for the compact index projection — an empty list is rejected, not treated as omission. Common leaves: NCTId, BriefTitle, BriefSummary, OverallStatus, Phase, LeadSponsorName, Condition. Call clinicaltrials_get_field_definitions with a concept query (e.g., \"adverse events\", \"eligibility\") to find the exact leaf for any concept."New value: +"PascalCase leaf names to return; strongly recommended since full records are ~70KB. Omit for the compact index projection — an empty list is rejected, not treated as omission. A comma- or pipe-joined entry (\"NCTId,BriefTitle\") is split into separate names. Common leaves: NCTId, BriefTitle, BriefSummary, OverallStatus, Phase, LeadSponsorName, Condition. Call clinicaltrials_get_field_definitions with a concept query (e.g., \"adverse events\", \"eligibility\") to find the exact leaf for any concept."

Previous value: -"Pagination cursor from a previous response."New value: +"Pagination cursor: a previous response's nextPageToken, passed back unchanged with the same criteria. Tokens expire when ClinicalTrials.gov refreshes its data."

Previous value: -"Filter by trial phase. Omit to search all phases — an empty list is rejected, not treated as \"no filter\". Values: EARLY_PHASE1, PHASE1, PHASE2, PHASE3, PHASE4, NA."New value: +"Filter by trial phase. Omit to search all phases — an empty list is rejected, not treated as \"no filter\". Values: EARLY_PHASE1, PHASE1, PHASE2, PHASE3, PHASE4, NA. Case and spacing variants (\"Phase 3\", \"early phase 1\", \"Not Applicable\") are accepted, and a list or a comma- or pipe-joined string matches any of the phases. Each entry must name a phase — put search expressions (OR, NOT, AREA[…]) in advancedFilter."

Previous value: -"Machine-readable failure mode. Declared by this tool: `blank_value`: A parameter was supplied with a blank, whitespace-only, or empty-list value. `ids_not_found`: One or more NCT IDs in the nctIds filter are not present at ClinicalTrials.gov. `field_invalid`: A field name in the fields parameter or AREA[] expression is invalid (often a module name instead of a piece name). `enum_invalid`: statusFilter or phaseFilter contains a value ClinicalTrials.gov does not accept. `query_parse_error`: A free-text query or advancedFilter expression uses syntax the upstream Essie parser rejects — typically a `[` or `]` outside an AREA[…] / RANGE[…] expression, an unmatched `(` / `)`, or an unterminated quote in a query/conditionQuery/etc. value. `geo_invalid`: geoFilter is not a well-formed distance(lat,lon,radius) expression. `sort_invalid`: sort is not FieldName:asc / FieldName:desc, or names more than 2 fields. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `blank_value`: A parameter was supplied with a blank, whitespace-only, or empty-list value. A fields or phaseFilter entry of only invisible format characters (zero-width space) is blank, and so is a phaseFilter entry of only quotes. `ids_not_found`: One or more NCT IDs in the nctIds filter are not present at ClinicalTrials.gov. `field_invalid`: A field name in the fields parameter or AREA[] expression is invalid (often a module name instead of a piece name). `enum_invalid`: A phaseFilter entry resolves to none of the six phase values, or statusFilter or an AREA[] expression carries a value ClinicalTrials.gov does not accept. `query_parse_error`: A free-text query or advancedFilter expression uses syntax the upstream Essie parser rejects — typically a `[` or `]` outside an AREA[…] / RANGE[…] expression, an unmatched `(` / `)`, or an unterminated quote in a query/conditionQuery/etc. value. `geo_invalid`: geoFilter is not a well-formed distance(lat,lon,radius) expression. `sort_invalid`: sort is not FieldName:asc / FieldName:desc, or names more than 2 fields. `page_token_invalid`: ClinicalTrials.gov rejected pageToken as malformed (not a token it issued), or as unresumable (issued before a data refresh, or altered after issue). `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler."

Previous value: -[
-  "blank_value",
-  "ids_not_found",
-  "field_invalid",
-  "enum_invalid",
-  "query_parse_error",
-  "geo_invalid",
-  "sort_invalid",
-  "rate_limited"
-]New value: +[
+  "blank_value",
+  "ids_not_found",
+  "field_invalid",
+  "enum_invalid",
+  "query_parse_error",
+  "geo_invalid",
+  "sort_invalid",
+  "page_token_invalid",
+  "rate_limited"
+]

Previous value: -"Echo of the explicit fields parameter — present only when the caller passed fields. Signals that studies carry the requested leaves at full fidelity (not the default compact index) and that the rendered truncation cap is lifted so all of them appear."New value: +"Echo of the explicit fields parameter, with comma- or pipe-joined entries split into separate names and repeated names listed once — present only when the caller passed fields. Signals that studies carry the requested leaves at full fidelity (not the default compact index) and that the rendered truncation cap is lifted so all of them appear."

Previous value: -"Cap on the sites returned per candidate. Each candidate keeps only the sites matching the requested location at the narrowest level that matched (city, else state, else country), capped at this many; the rest of the study's registered sites are omitted. The cap governs those matched sites — when none of them is recruiting, the candidate's nearest recruiting site is added on top of it, so a candidate can carry one site more than this. Raise it to see more nearby sites, or fetch the complete site list with clinicaltrials_get_study_record. Each candidate reports totalLocations / matchedLocations / locationsTruncated / nearestRecruitingSiteAdded in locationSummary only when the bound actually dropped sites."New value: +"Cap on the sites returned per candidate. Each candidate keeps only the sites matching the requested location at the narrowest level that matched (city, else state, else country), capped at this many; the rest of the study's registered sites are omitted. The cap governs those matched sites — when none of them is recruiting, one recruiting site is added on top of it (the nearest to any matched site, measured before this cap, when coordinates allow — in the requested country whenever a site there recruits), so a candidate can carry one site more than this. Raise it to see more nearby sites, or fetch the complete site list with clinicaltrials_get_study_record. Each candidate reports totalLocations / matchedLocations / locationsTruncated / nearestRecruitingSiteAdded in locationSummary only when the bound actually dropped sites."

Previous value: -"Matching studies with eligibility and location fields. Each candidate's protocolSection.contactsLocationsModule.locations is BOUNDED to the sites matching the requested location (capped at locationLimit) plus, when none of those is recruiting, the candidate's nearest recruiting site — not the study's full registered site list. A candidate whose sites were bounded also carries a top-level locationSummary object — { totalLocations, matchedLocations, locationsTruncated, nearestRecruitingSiteAdded?, retrieveFullStudyWith } — absent when nothing was dropped; nearestRecruitingSiteAdded is present only when that extra site was added. Fetch a study's complete record and site list with clinicaltrials_get_study_record."New value: +"Matching studies with eligibility and location fields. Each candidate's protocolSection.contactsLocationsModule.locations is BOUNDED to the sites matching the requested location (capped at locationLimit) plus, when none of those is recruiting, one added recruiting site — not the study's full registered site list. The added site is the one nearest any matched site by published coordinates, taken from the requested country whenever a site there recruits, and carries distanceMi (miles to that nearest matched site); when the matched or recruiting sites publish no coordinates it is the first in match order and carries no distanceMi. A candidate whose sites were bounded also carries a top-level locationSummary object — { totalLocations, matchedLocations, locationsTruncated, nearestRecruitingSiteAdded?, retrieveFullStudyWith } — absent when nothing was dropped; nearestRecruitingSiteAdded is present only when that extra site was added (the key keeps its name in the match-order fallback). Fetch a study's complete record and site list with clinicaltrials_get_study_record."

Previous value: -"Optional cap on the number of serious and other adverse events returned per study, applied to each list separately in upstream order. Omit for no cap (every event). Applies to full mode only — summary mode already ranks the top 20 by participants affected. Event groups are never capped. Upstream totals preserved in filtersApplied.totalSeriousEvents / totalOtherEvents only when the cap trims a list."New value: +"Optional cap on the number of serious and other adverse events returned per study, applied to each list separately in upstream order. Omit for no cap (every event). Applies to full mode only — summary mode already ranks the top 20 by the most participants affected in any one event group. Event groups are never capped. Upstream totals preserved in filtersApplied.totalSeriousEvents / totalOtherEvents only when the cap trims a list."

Previous value: -"Adverse events. Summary mode: timeFrame, groupCount, seriousEventCount, otherEventCount, plus topEvents — the most frequent events ranked by participants affected, aggregated across arms (term, organSystem, kind, numAffected, numAtRisk). Full mode: adds eventGroups, seriousEvents, otherEvents with per-event term and per-group affected/at-risk stats."New value: +"Adverse events. Summary mode: timeFrame, groupCount, seriousEventCount, otherEventCount, eventGroups (id and title of each event group), plus topEvents — up to 20 events ranked by the most participants affected in any one event group, each with term, organSystem, kind, and byGroup (one { groupId, numAffected, numAtRisk } row per event group; resolve groupId against eventGroups). Counts are never pooled across groups: groups can overlap (a crossover or second-course group re-counts participants of its parent arm), so compare arms row by row. Full mode: eventGroups with descriptions and per-group totals, plus seriousEvents and otherEvents with per-event term and per-group affected/at-risk stats."

Removed value: -[
-  "nctIds"
-]

Previous value: -"The NCT identifier as requested, echoed verbatim. When it is a previous (alias) ID, ClinicalTrials.gov answers with the canonical record and canonicalNctId names it."New value: +"The NCT identifier as requested, trimmed and uppercased. When it is a previous (alias) ID, ClinicalTrials.gov answers with the canonical record and canonicalNctId names it."

Previous value: -"Advanced filter using AREA[FieldName]value syntax. Examples: \"AREA[StudyType]INTERVENTIONAL\", \"AREA[EnrollmentCount]RANGE[100, 1000]\", \"AREA[Phase]PHASE2 AND AREA[StudyType]INTERVENTIONAL\", \"(AREA[Phase]PHASE3 OR AREA[Phase]PHASE4) AND AREA[StudyType]INTERVENTIONAL\". AND/OR/NOT join complete AREA[FieldName]value expressions; parentheses group them. Call clinicaltrials_get_field_definitions to find AREA[]-compatible field names."New value: +"Advanced filter using AREA[FieldName]value syntax. Examples: \"AREA[StudyType]INTERVENTIONAL\", \"AREA[EnrollmentCount]RANGE[100, 1000]\", \"AREA[Phase]PHASE2 AND AREA[StudyType]INTERVENTIONAL\", \"(AREA[Phase]PHASE3 OR AREA[Phase]PHASE4) AND AREA[StudyType]INTERVENTIONAL\". \"AREA[HasResults]true\" restricts to studies with posted results. AND/OR/NOT join complete AREA[FieldName]value expressions; parentheses group them. Call clinicaltrials_get_field_definitions to find AREA[]-compatible field names."

Previous value: -"Matching studies. By default each entry is a COMPACT index projection — nctId, briefTitle, overallStatus, phases, enrollmentCount, leadSponsor, conditions, and a bounded locations summary ({ total, nearest }) — mirroring the rendered result, NOT the full ~70KB record. Pass the fields parameter to receive exactly the requested leaves at full fidelity instead (e.g. all locations). Fetch a full single record with clinicaltrials_get_study_record."New value: +"Matching studies. By default each entry is a COMPACT index projection — nctId, briefTitle, overallStatus, phases, enrollmentCount, leadSponsor, conditions, hasResults, startDate and primaryCompletionDate (YYYY-MM or YYYY-MM-DD, as registered), and a bounded locations summary ({ total, nearest }); keys the study does not publish are omitted — mirroring the rendered result, NOT the full ~70KB record. Pass the fields parameter to receive exactly the requested leaves at full fidelity instead (e.g. all locations). Fetch a full single record with clinicaltrials_get_study_record."

Previous value: -"Machine-readable failure mode. Declared by this tool: `path_not_found`: The dot-notation path does not match any node in the field tree. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `blank_value`: The selected mode's required argument was supplied with a whitespace-only value. `mode_mismatch`: An argument belonging to a different mode was supplied alongside the selected mode. `mode_requires`: The selected mode's required argument was omitted. `path_not_found`: The dot-notation path does not match any node in the field tree. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler."

Previous value: -[
-  "path_not_found",
-  "rate_limited"
-]New value: +[
+  "blank_value",
+  "mode_mismatch",
+  "mode_requires",
+  "path_not_found",
+  "rate_limited"
+]

Previous value: -"One entry per requested field: canonical path, PascalCase piece name, data type, missing/unique counts, and top values with study counts (or trueCount/falseCount for BOOLEAN fields)."New value: +"One entry per requested field: canonical path, PascalCase piece name, data type, and the statistics variant that type carries — top values with study counts plus unique/longest for ENUM/STRING, trueCount/falseCount for BOOLEAN, min/max/avg for INTEGER/NUMBER, min/max/formats for DATE."

Added value: +{
+  "description": "Mean of the recorded values. Present for INTEGER/NUMBER fields.",
+  "type": "number"
+}

Added value: +{
+  "description": "Date patterns this field is recorded in. Present for DATE fields; more than one means the field mixes precisions across studies.",
+  "items": {
+    "description": "A date pattern, e.g. \"yyyy-MM-dd\".",
+    "type": "string"
+  },
+  "type": "array"
+}

Added value: +{
+  "additionalProperties": false,
+  "description": "Longest recorded value with its length and a study carrying it. Present for STRING fields only.",
+  "properties": {
+    "length": {
+      "description": "Its length in characters.",
+      "type": "number"
+    },
+    "nctId": {
+      "description": "NCT ID of a study carrying it.",
+      "type": "string"
+    },
+    "value": {
+      "description": "The longest recorded value.",
+      "type": "string"
+    }
+  },
+  "required": [
+    "value",
+    "length",
+    "nctId"
+  ],
+  "type": "object"
+}

Added value: +{
+  "anyOf": [
+    {
+      "description": "Largest value of an INTEGER/NUMBER field.",
+      "type": "number"
+    },
+    {
+      "description": "Latest value of a DATE field, at the precision recorded.",
+      "type": "string"
+    }
+  ],
+  "description": "Largest recorded value — a number for INTEGER/NUMBER, a date string for DATE."
+}

Added value: +{
+  "anyOf": [
+    {
+      "description": "Smallest value of an INTEGER/NUMBER field.",
+      "type": "number"
+    },
+    {
+      "description": "Earliest value of a DATE field, at the precision recorded — a partial date such as \"1900-01\" stays partial.",
+      "type": "string"
+    }
+  ],
+  "description": "Smallest recorded value — a number for INTEGER/NUMBER, a date string for DATE."
+}

Previous value: -"True when the field is array-typed (a study can carry several values, e.g. Phase, Condition), so the per-value studiesCount buckets sum above the study total. Use to avoid computing a percentage against the corpus."New value: +"True when the field is repeated — array-typed itself (Phase, Condition) or nested under a repeated object (LocationCountry, one per site) — so a study can carry several values and the per-value studiesCount buckets sum above the study total. Use to avoid computing a percentage against the corpus."

Previous value: -"Recovery guidance when no studies matched — echoes the constraint and suggests how to broaden. Absent on pages with results, and on an exhausted continuation page, where the cohort already matched and there is nothing to broaden."New value: +"Recovery guidance when no studies matched — echoes the constraint and suggests how to broaden, and names nctIds as part of the unmatched criteria when an ID list was supplied. Absent on pages with results, and on an exhausted continuation page, where the cohort already matched and there is nothing to broaden."

Previous value: -"The exact queryLocn string sent upstream (city/state/country joined). Pass as locationQuery to clinicaltrials_search_studies to reproduce the location filter beyond the maxResults cap."New value: +"The exact queryLocn string sent upstream (city/state/country, multi-word components quoted, AND-joined). Pass as locationQuery to clinicaltrials_search_studies to reproduce the location filter beyond the maxResults cap."

Previous value: -"Geographic proximity filter. Format: distance(lat,lon,radius), where radius carries a `mi` or `km` suffix — e.g. \"distance(47.6062,-122.3321,50mi)\" for studies within 50 miles of Seattle. Always include the suffix: a bare radius is accepted upstream but interpreted as meters, which silently matches almost nothing. When set, each study's locations are re-sorted by proximity to the center so the nearest matched site leads, annotated with its distance in miles; the full location list is preserved."New value: +"Geographic proximity filter. Format: distance(lat,lon,radius), where radius carries a `mi` or `km` suffix — e.g. \"distance(47.6062,-122.3321,50mi)\" for studies within 50 miles of Seattle. The suffix is required: a radius with no unit is rejected, as are a non-positive radius, a latitude outside [-90, 90], and a longitude outside [-180, 180]. When set, each study's locations are re-sorted by proximity to the center so the nearest matched site leads, annotated with its distance in miles; the full location list is preserved."

Previous value: -"Recovery guidance when no studies matched — echoes the constraint and suggests how to broaden. Absent on pages with results."New value: +"Recovery guidance when no studies matched — echoes the constraint and suggests how to broaden. Absent on pages with results, and on an exhausted continuation page, where the cohort already matched and there is nothing to broaden."

Added value: +{
+  "description": "True when this call supplied a pageToken and the continuation page came back empty — the walk is finished and no further pages exist. Absent on every other response, including an empty first page, which is an unmatched search rather than exhausted pagination.",
+  "type": "boolean"
+}

Previous value: -"One or more NCT IDs (max 20) — an empty list is rejected. E.g., \"NCT12345678\" or [\"NCT12345678\", \"NCT87654321\"]. Use summary=true for large batches to avoid large payloads."New value: +"One or more NCT IDs (max 20) — an empty list is rejected, and a repeated ID collapses to one results entry in first-occurrence order. E.g., \"NCT12345678\" or [\"NCT12345678\", \"NCT87654321\"]. Use summary=true for large batches to avoid large payloads."

Added value: +{
+  "description": "Optional index of the first other (non-serious) adverse event to return, in upstream order. Omit or 0 to start at the first. Pages independently of seriousEventOffset and pairs with adverseEventLimit. Continue from filtersApplied.nextOtherEventOffset until that field is absent. Applied to every study in the call. Rejected with summary: true or when sections excludes adverseEvents.",
+  "maximum": 9007199254740991,
+  "minimum": 0,
+  "type": "integer"
+}

Added value: +{
+  "description": "Optional index of the first outcome measure to return, in the order ClinicalTrials.gov publishes them. Omit or 0 to start at the first. Pair with outcomeLimit to page a long list: each response reports filtersApplied.nextOutcomeOffset for the study, and the list is exhausted when that field is absent. Applied to every study in the call. An offset at or past the end returns an empty list with filtersApplied.totalOutcomes stating the upstream length, not an error. Rejected with summary: true or when sections excludes outcomes.",
+  "maximum": 9007199254740991,
+  "minimum": 0,
+  "type": "integer"
+}

Added value: +{
+  "description": "Optional index of the first serious adverse event to return, in upstream order. Omit or 0 to start at the first. Pages independently of otherEventOffset — the two lists have uncorrelated lengths — and pairs with adverseEventLimit, which bounds each list separately. Continue from filtersApplied.nextSeriousEventOffset until that field is absent. Applied to every study in the call. Rejected with summary: true or when sections excludes adverseEvents.",
+  "maximum": 9007199254740991,
+  "minimum": 0,
+  "type": "integer"
+}

Previous value: -"Return condensed summaries instead of full data. Full mode renders every row and field on both output channels, so a large results set can exceed 500KB per study; summary mode reduces that to ~5KB. Summaries include outcome titles, types, timeframes, group counts, and top-level stats — omitting individual measurements, analyses, and per-group data. For a middle ground, keep full mode and cap the two lists that carry the bulk with outcomeLimit / adverseEventLimit."New value: +"Return condensed summaries instead of full data. Full mode renders every row and field on both output channels, so a large results set can exceed 500KB per study; summary mode typically cuts that to a few KB, scaling with the measure count rather than to a fixed ceiling. An outcome summary keeps the title, type, timeframe, paramType, dispersionType, unit, group/class counts, per-group denominators, one statistical analysis, and a top-line projection of a single class/category cell — labelled with the class and category titles it came from and a count of the siblings it omits. The measurements outside that cell and the remaining analyses are dropped; re-run with summary=false to reach them. For a middle ground, keep full mode and cap the two lists that carry the bulk with outcomeLimit / adverseEventLimit."

Previous value: -"Machine-readable failure mode. Declared by this tool: `blank_value`: A parameter was supplied with a blank, whitespace-only, or empty-list value. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler."New value: +"Machine-readable failure mode. Declared by this tool: `blank_value`: A parameter was supplied with a blank, whitespace-only, or empty-list value. `offset_not_applicable`: An offset was supplied for a list this call does not return — summary mode returns a condensed projection rather than a bounded window, or the sections filter excludes the offset’s own section. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler."

Previous value: -[
-  "blank_value",
-  "rate_limited"
-]New value: +[
+  "blank_value",
+  "offset_not_applicable",
+  "rate_limited"
+]

Added value: +{
+  "description": "The canonical NCT identifier of the study that answered — present only when the requested nctId is a previous (alias) ID pointing at a different record. Absent means nctId is already canonical. Requesting an alias and its own canonical ID together returns one entry per requested ID, both carrying the same study.",
+  "type": "string"
+}

Previous value: -"What a cap trimmed on this study — present only when a cap actually reduced a list. Absent means the payload is the complete upstream set for the requested sections."New value: +"What the outcomeLimit / adverseEventLimit caps and the outcomeOffset / seriousEventOffset / otherEventOffset offsets trimmed on this study, plus the next offset for each list left short. Present only when a bound actually reduced a list — a window that started at zero and reached the end trimmed nothing. Absent means the payload is the complete upstream set for the requested sections. Offsets apply uniformly to every study in the call, so continuation is reported per study: each exhausts its lists at a different index."

Previous value: -"Echo of the adverseEventLimit input — present only when the cap trimmed a list."New value: +"Echo of the adverseEventLimit input — present only when the cap cut events off the end of a window. Which list it cut is named by that list’s own next offset."

Added value: +{
+  "description": "The otherEventOffset to request next for this study — present only when other events remain past the window. Absent means this study’s other event list is exhausted.",
+  "maximum": 9007199254740991,
+  "minimum": -9007199254740991,
+  "type": "integer"
+}

Added value: +{
+  "description": "The outcomeOffset to request next for this study — present only when measures remain past the window. Absent means this study’s outcome list is exhausted.",
+  "maximum": 9007199254740991,
+  "minimum": -9007199254740991,
+  "type": "integer"
+}

Added value: +{
+  "description": "The seriousEventOffset to request next for this study — present only when serious events remain past the window. Absent means this study’s serious event list is exhausted.",
+  "maximum": 9007199254740991,
+  "minimum": -9007199254740991,
+  "type": "integer"
+}

Added value: +{
+  "description": "Echo of the otherEventOffset input — present only when it skipped events before the window.",
+  "maximum": 9007199254740991,
+  "minimum": -9007199254740991,
+  "type": "integer"
+}

Previous value: -"Echo of the outcomeLimit input — present only when the cap trimmed the list."New value: +"Echo of the outcomeLimit input — present only when the cap cut measures off the end of the window."

Added value: +{
+  "description": "Echo of the outcomeOffset input — present only when it skipped measures before the window.",
+  "maximum": 9007199254740991,
+  "minimum": -9007199254740991,
+  "type": "integer"
+}

Added value: +{
+  "description": "Echo of the seriousEventOffset input — present only when it skipped events before the window.",
+  "maximum": 9007199254740991,
+  "minimum": -9007199254740991,
+  "type": "integer"
+}

Previous value: -"Upstream other adverse event count before adverseEventLimit trimmed the list."New value: +"Upstream other adverse event count, before the bounds trimmed the list."

Previous value: -"Upstream outcome measure count before outcomeLimit trimmed the list."New value: +"Upstream outcome measure count, before the bounds trimmed the list."

Previous value: -"Upstream serious adverse event count before adverseEventLimit trimmed the list."New value: +"Upstream serious adverse event count, before the bounds trimmed the list."

Previous value: -"NCT identifier."New value: +"The NCT identifier as requested, echoed verbatim. When it is a previous (alias) ID, ClinicalTrials.gov answers with the canonical record and canonicalNctId names it."

Previous value: -"Outcome measures with per-group statistics. Summary mode (compact): type, title, timeFrame, paramType, unitOfMeasure, group/class counts, plus topStats (per-group measurements) and topAnalysis (statisticalMethod, pValue, paramType/Value, ciPctValue/Lower/Upper, nonInferiorityType, groupIds — lifted from analyses[0]) when present. Full mode (default): adds raw groups, classes, categories, measurements, and analyses arrays."New value: +"Outcome measures with per-group statistics. Summary mode (compact): type, title, timeFrame, paramType, dispersionType, unitOfMeasure, group/class counts, denoms (per-group denominators keyed by group title), topStats (the per-group cells of one class/category — each carrying the upstream value verbatim, including an NA/NR sentinel, plus spread, lowerLimit/upperLimit, and the record’s own comment when present), topStatsFrom (classTitle / categoryTitle naming where that cell came from, with omittedClasses / omittedCategories counts and a note pointing at summary=false when siblings were dropped), and topAnalysis (statisticalMethod, pValue, paramType/Value, ciPctValue/Lower/Upper, nonInferiorityType, groupIds — lifted from analyses[0]) when present. Full mode (default): adds raw groups, classes, categories, measurements, and analyses arrays."

Previous value: -"True when a cap trimmed a list on at least one study; absent when nothing was trimmed, matching filtersApplied one level down. Which study and which list is named in that study’s filtersApplied."New value: +"True when a bound — a cap or an offset — trimmed a list on at least one study; absent when nothing was trimmed, matching filtersApplied one level down. Which study, which list, and where to resume is named in that study’s filtersApplied."

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

Added value: +false

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": [
+      "studies",
+      "searchCriteria",
+      "funnel"
+    ]
+  },
+  {
+    "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: `blank_value`: A parameter was supplied with a blank, whitespace-only, or empty-list value. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler.",
+          "examples": [
+            "blank_value",
+            "rate_limited"
+          ],
+          "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: -[
-  "studies",
-  "searchCriteria",
-  "funnel"
-]

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": [
+      "fields",
+      "totalFields"
+    ]
+  },
+  {
+    "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: `path_not_found`: The dot-notation path does not match any node in the field tree. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler.",
+          "examples": [
+            "path_not_found",
+            "rate_limited"
+          ],
+          "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: -[
-  "fields",
-  "totalFields"
-]

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": [
+      "fieldStats"
+    ]
+  },
+  {
+    "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: `blank_value`: A parameter was supplied with a blank, whitespace-only, or empty-list value. `field_invalid`: A requested field name is not a valid PascalCase piece name. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler.",
+          "examples": [
+            "blank_value",
+            "field_invalid",
+            "rate_limited"
+          ],
+          "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: -[
-  "fieldStats"
-]

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": [
+      "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: `blank_value`: A parameter was supplied with a blank, whitespace-only, or empty-list value. `field_invalid`: A field name in the advanced filter or AREA[] expression is invalid (often a module name instead of a piece name). `enum_invalid`: statusFilter or phaseFilter contains a value ClinicalTrials.gov does not accept. `query_parse_error`: A free-text query or advancedFilter expression uses syntax the upstream Essie parser rejects — typically a `[` or `]` outside an AREA[…] / RANGE[…] expression, an unmatched `(` / `)`, or an unterminated quote in a query/conditionQuery/etc. value. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler.",
+          "examples": [
+            "blank_value",
+            "field_invalid",
+            "enum_invalid",
+            "query_parse_error",
+            "rate_limited"
+          ],
+          "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: -[
-  "totalCount"
-]

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

Added value: +false

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": [
+      "study",
+      "filtersApplied"
+    ]
+  },
+  {
+    "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: `study_not_found`: The provided NCT ID does not match any study at ClinicalTrials.gov. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler.",
+          "examples": [
+            "study_not_found",
+            "rate_limited"
+          ],
+          "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: -[
-  "study",
-  "filtersApplied"
-]

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": [
+      "results"
+    ]
+  },
+  {
+    "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: `blank_value`: A parameter was supplied with a blank, whitespace-only, or empty-list value. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler.",
+          "examples": [
+            "blank_value",
+            "rate_limited"
+          ],
+          "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"
-]

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": [
+      "studies"
+    ]
+  },
+  {
+    "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: `blank_value`: A parameter was supplied with a blank, whitespace-only, or empty-list value. `ids_not_found`: One or more NCT IDs in the nctIds filter are not present at ClinicalTrials.gov. `field_invalid`: A field name in the fields parameter or AREA[] expression is invalid (often a module name instead of a piece name). `enum_invalid`: statusFilter or phaseFilter contains a value ClinicalTrials.gov does not accept. `query_parse_error`: A free-text query or advancedFilter expression uses syntax the upstream Essie parser rejects — typically a `[` or `]` outside an AREA[…] / RANGE[…] expression, an unmatched `(` / `)`, or an unterminated quote in a query/conditionQuery/etc. value. `geo_invalid`: geoFilter is not a well-formed distance(lat,lon,radius) expression. `sort_invalid`: sort is not FieldName:asc / FieldName:desc, or names more than 2 fields. `rate_limited`: ClinicalTrials.gov returned 429 after retry budget exhausted. Other values are possible when a failure originates below the handler.",
+          "examples": [
+            "blank_value",
+            "ids_not_found",
+            "field_invalid",
+            "enum_invalid",
+            "query_parse_error",
+            "geo_invalid",
+            "sort_invalid",
+            "rate_limited"
+          ],
+          "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: -[
-  "studies"
-]

Added value: +{
+  "default": 10,
+  "description": "Cap on the sites returned per candidate. Each candidate keeps only the sites matching the requested location at the narrowest level that matched (city, else state, else country), capped at this many; the rest of the study's registered sites are omitted. The cap governs those matched sites — when none of them is recruiting, the candidate's nearest recruiting site is added on top of it, so a candidate can carry one site more than this. Raise it to see more nearby sites, or fetch the complete site list with clinicaltrials_get_study_record. Each candidate reports totalLocations / matchedLocations / locationsTruncated / nearestRecruitingSiteAdded in locationSummary only when the bound actually dropped sites.",
+  "maximum": 500,
+  "minimum": 1,
+  "type": "integer"
+}

Previous value: -"Matching studies with eligibility and location fields."New value: +"Matching studies with eligibility and location fields. Each candidate's protocolSection.contactsLocationsModule.locations is BOUNDED to the sites matching the requested location (capped at locationLimit) plus, when none of those is recruiting, the candidate's nearest recruiting site — not the study's full registered site list. A candidate whose sites were bounded also carries a top-level locationSummary object — { totalLocations, matchedLocations, locationsTruncated, nearestRecruitingSiteAdded?, retrieveFullStudyWith } — absent when nothing was dropped; nearestRecruitingSiteAdded is present only when that extra site was added. Fetch a study's complete record and site list with clinicaltrials_get_study_record."

Added value: +{
+  "description": "Optional cap on the number of serious and other adverse events returned per study, applied to each list separately in upstream order. Omit for no cap (every event). Applies to full mode only — summary mode already ranks the top 20 by participants affected. Event groups are never capped. Upstream totals preserved in filtersApplied.totalSeriousEvents / totalOtherEvents only when the cap trims a list.",
+  "maximum": 500,
+  "minimum": 1,
+  "type": "integer"
+}

Added value: +{
+  "description": "Optional cap on the number of outcome measures returned per study, taken in the order ClinicalTrials.gov publishes them. Omit for no cap (every measure). Applies to full mode only — summary mode is already condensed. Each surviving measure keeps its complete groups/classes/measurements/analyses tree. Upstream total preserved in filtersApplied.totalOutcomes only when the cap trims the list.",
+  "maximum": 100,
+  "minimum": 1,
+  "type": "integer"
+}

Previous value: -"Return condensed summaries instead of full data. Full mode renders every row and field on both output channels, so a large results set can exceed 500KB per study; summary mode reduces that to ~5KB. Summaries include outcome titles, types, timeframes, group counts, and top-level stats — omitting individual measurements, analyses, and per-group data."New value: +"Return condensed summaries instead of full data. Full mode renders every row and field on both output channels, so a large results set can exceed 500KB per study; summary mode reduces that to ~5KB. Summaries include outcome titles, types, timeframes, group counts, and top-level stats — omitting individual measurements, analyses, and per-group data. For a middle ground, keep full mode and cap the two lists that carry the bulk with outcomeLimit / adverseEventLimit."

Added value: +{
+  "additionalProperties": false,
+  "description": "What a cap trimmed on this study — present only when a cap actually reduced a list. Absent means the payload is the complete upstream set for the requested sections.",
+  "properties": {
+    "adverseEventLimit": {
+      "description": "Echo of the adverseEventLimit input — present only when the cap trimmed a list.",
+      "maximum": 9007199254740991,
+      "minimum": -9007199254740991,
+      "type": "integer"
+    },
+    "outcomeLimit": {
+      "description": "Echo of the outcomeLimit input — present only when the cap trimmed the list.",
+      "maximum": 9007199254740991,
+      "minimum": -9007199254740991,
+      "type": "integer"
+    },
+    "totalOtherEvents": {
+      "description": "Upstream other adverse event count before adverseEventLimit trimmed the list.",
+      "maximum": 9007199254740991,
+      "minimum": -9007199254740991,
+      "type": "integer"
+    },
+    "totalOutcomes": {
+      "description": "Upstream outcome measure count before outcomeLimit trimmed the list.",
+      "maximum": 9007199254740991,
+      "minimum": -9007199254740991,
+      "type": "integer"
+    },
+    "totalSeriousEvents": {
+      "description": "Upstream serious adverse event count before adverseEventLimit trimmed the list.",
+      "maximum": 9007199254740991,
+      "minimum": -9007199254740991,
+      "type": "integer"
+    }
+  },
+  "type": "object"
+}

Added value: +{
+  "description": "True when a cap trimmed a list on at least one study; absent when nothing was trimmed, matching filtersApplied one level down. Which study and which list is named in that study’s filtersApplied.",
+  "type": "boolean"
+}

Removed value: -1

Previous value: -[
-  {
-    "description": "A single PascalCase field name.",
-    "type": "string"
-  },
-  {
-    "description": "Multiple PascalCase field names (at least one required).",
-    "items": {
-      "type": "string"
-    },
-    "minItems": 1,
-    "type": "array"
-  }
-]New value: +[
+  {
+    "description": "A single PascalCase field name.",
+    "type": "string"
+  },
+  {
+    "description": "Multiple PascalCase field names (at least one required).",
+    "items": {
+      "type": "string"
+    },
+    "type": "array"
+  }
+]

Previous value: -"PascalCase field name(s) to get value statistics for. Examples: OverallStatus, Phase, StudyType, Sex, LeadSponsorClass. Use clinicaltrials_get_field_definitions with a query to find more field names."New value: +"PascalCase field name(s) to get value statistics for — an empty list is rejected, not treated as \"every field\". Examples: OverallStatus, Phase, StudyType, Sex, LeadSponsorClass. Use clinicaltrials_get_field_definitions with a query to find more field names."

Previous value: -"Condition/disease-specific search. E.g., \"Type 2 Diabetes\", \"non-small cell lung cancer\". Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."New value: +"Condition/disease-specific search. E.g., \"Type 2 Diabetes\", \"non-small cell lung cancer\". Matches Condition, BriefTitle, OfficialTitle, ConditionMeshTerm, ConditionAncestorTerm, Keyword, and NCTId. ConditionAncestorTerm is the MeSH umbrella above the conditions a study itself lists, so results run broader than those lists — a study can match a parent term it never names. Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."

Previous value: -"Intervention/treatment search. E.g., \"pembrolizumab\", \"cognitive behavioral therapy\". Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."New value: +"Intervention/treatment search. E.g., \"pembrolizumab\", \"cognitive behavioral therapy\". Matches InterventionName, InterventionType, ArmGroupType, InterventionOtherName, BriefTitle, OfficialTitle, ArmGroupLabel, InterventionMeshTerm, Keyword, InterventionAncestorTerm, InterventionDescription, and ArmGroupDescription. InterventionAncestorTerm is the MeSH umbrella above the interventions a study itself lists, so results run broader than those lists. Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."

Previous value: -"Location search — city, state, country, or facility name. Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."New value: +"Location search — city, state, country, or facility name. Matches LocationCity, LocationState, LocationCountry, LocationFacility, and LocationZip; a study matches when any of its sites does. Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."

Previous value: -"Search within outcome measure fields. Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."New value: +"Search within outcome measure fields. Matches PrimaryOutcomeMeasure, SecondaryOutcomeMeasure, OtherOutcomeMeasure, and OutcomeMeasureTitle, plus their description counterparts PrimaryOutcomeDescription, SecondaryOutcomeDescription, OtherOutcomeDescription, OutcomeMeasureDescription, and OutcomeMeasurePopulationDescription — so a term appearing only in outcome prose still matches. Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."

Previous value: -[
-  {
-    "description": "A single phase value.",
-    "type": "string"
-  },
-  {
-    "description": "Multiple phase values (OR).",
-    "items": {
-      "type": "string"
-    },
-    "minItems": 1,
-    "type": "array"
-  }
-]New value: +[
+  {
+    "description": "A single phase value.",
+    "type": "string"
+  },
+  {
+    "description": "Multiple phase values (OR).",
+    "items": {
+      "type": "string"
+    },
+    "type": "array"
+  }
+]

Previous value: -"General free-text search across all fields. Plain words plus AND, OR, NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression — those work here as well as in advancedFilter, so AREA[Phase]PHASE2 is accepted in this parameter; a stray bracket fails. `( )` group sub-expressions and work when matched; `,` acts as AND. The dedicated *Query parameters (conditionQuery, interventionQuery, etc.) scope a search to one field."New value: +"General free-text search across all fields. Runs the 57-field relevance search ClinicalTrials.gov publishes for this parameter — NCTId, NCTIdAlias, OrgStudyId, SecondaryId, Acronym, BriefTitle, OfficialTitle, Condition, InterventionName, InterventionOtherName, Phase, StdAge, StudyType, BriefSummary, outcome measures and their descriptions, LeadSponsorName, CollaboratorName, the Location* fields, the Design* fields, and the ConditionAncestorTerm/InterventionAncestorTerm MeSH umbrellas — so a hit need not carry your term in the field you had in mind. Plain words plus AND, OR, NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression — those work here as well as in advancedFilter, so AREA[Phase]PHASE2 is accepted in this parameter; a stray bracket fails. `( )` group sub-expressions and work when matched; `,` acts as AND. The dedicated *Query parameters (conditionQuery, interventionQuery, etc.) scope a search to one field."

Previous value: -"Sponsor/collaborator name search. Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."New value: +"Sponsor/collaborator name search. Matches LeadSponsorName, CollaboratorName, and OrgFullName. Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."

Previous value: -[
-  {
-    "description": "A single status value.",
-    "type": "string"
-  },
-  {
-    "description": "Multiple status values (OR).",
-    "items": {
-      "type": "string"
-    },
-    "minItems": 1,
-    "type": "array"
-  }
-]New value: +[
+  {
+    "description": "A single status value.",
+    "type": "string"
+  },
+  {
+    "description": "Multiple status values (OR).",
+    "items": {
+      "type": "string"
+    },
+    "type": "array"
+  }
+]

Previous value: -"Search within study titles and acronyms only. Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."New value: +"Search within study titles and acronyms only. Matches Acronym, BriefTitle, and OfficialTitle. Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."

Previous value: -[
-  {
-    "description": "A single NCT ID.",
-    "pattern": "^NCT\\d{8}$",
-    "type": "string"
-  },
-  {
-    "description": "Multiple NCT IDs (max 20).",
-    "items": {
-      "pattern": "^NCT\\d{8}$",
-      "type": "string"
-    },
-    "maxItems": 20,
-    "minItems": 1,
-    "type": "array"
-  }
-]New value: +[
+  {
+    "description": "A single NCT ID.",
+    "pattern": "^NCT\\d{8}$",
+    "type": "string"
+  },
+  {
+    "description": "Multiple NCT IDs (max 20).",
+    "items": {
+      "pattern": "^NCT\\d{8}$",
+      "type": "string"
+    },
+    "maxItems": 20,
+    "type": "array"
+  }
+]

Previous value: -"One or more NCT IDs (max 20). E.g., \"NCT12345678\" or [\"NCT12345678\", \"NCT87654321\"]. Use summary=true for large batches to avoid large payloads."New value: +"One or more NCT IDs (max 20) — an empty list is rejected. E.g., \"NCT12345678\" or [\"NCT12345678\", \"NCT87654321\"]. Use summary=true for large batches to avoid large payloads."

Previous value: -[
-  {
-    "description": "A single section name.",
-    "enum": [
-      "outcomes",
-      "adverseEvents",
-      "participantFlow",
-      "baseline",
-      "moreInfo"
-    ],
-    "type": "string"
-  },
-  {
-    "description": "Multiple section names.",
-    "items": {
-      "enum": [
-        "outcomes",
-        "adverseEvents",
-        "participantFlow",
-        "baseline",
-        "moreInfo"
-      ],
-      "type": "string"
-    },
-    "minItems": 1,
-    "type": "array"
-  }
-]New value: +[
+  {
+    "description": "A single section name.",
+    "enum": [
+      "outcomes",
+      "adverseEvents",
+      "participantFlow",
+      "baseline",
+      "moreInfo"
+    ],
+    "type": "string"
+  },
+  {
+    "description": "Multiple section names.",
+    "items": {
+      "enum": [
+        "outcomes",
+        "adverseEvents",
+        "participantFlow",
+        "baseline",
+        "moreInfo"
+      ],
+      "type": "string"
+    },
+    "type": "array"
+  }
+]

Previous value: -"Condition/disease-specific search. E.g., \"Type 2 Diabetes\", \"non-small cell lung cancer\". Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."New value: +"Condition/disease-specific search. E.g., \"Type 2 Diabetes\", \"non-small cell lung cancer\". Matches Condition, BriefTitle, OfficialTitle, ConditionMeshTerm, ConditionAncestorTerm, Keyword, and NCTId. ConditionAncestorTerm is the MeSH umbrella above the conditions a study itself lists, so results run broader than those lists — a study can match a parent term it never names. Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."

Removed value: -1

Previous value: -"Intervention/treatment search. E.g., \"pembrolizumab\", \"cognitive behavioral therapy\". Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."New value: +"Intervention/treatment search. E.g., \"pembrolizumab\", \"cognitive behavioral therapy\". Matches InterventionName, InterventionType, ArmGroupType, InterventionOtherName, BriefTitle, OfficialTitle, ArmGroupLabel, InterventionMeshTerm, Keyword, InterventionAncestorTerm, InterventionDescription, and ArmGroupDescription. InterventionAncestorTerm is the MeSH umbrella above the interventions a study itself lists, so results run broader than those lists. Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."

Previous value: -"Location search — city, state, country, or facility name. Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."New value: +"Location search — city, state, country, or facility name. Matches LocationCity, LocationState, LocationCountry, LocationFacility, and LocationZip; a study matches when any of its sites does. Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."

Previous value: -"Filter to specific NCT IDs for batch lookups."New value: +"Filter to specific NCT IDs for batch lookups. Omit to search every study — an empty list is rejected, not treated as \"no filter\". Supplying this lifts the default unknown-enrollment exclusion, so an ID you name is never filtered out of its own lookup."

Previous value: -"Search within outcome measure fields. Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."New value: +"Search within outcome measure fields. Matches PrimaryOutcomeMeasure, SecondaryOutcomeMeasure, OtherOutcomeMeasure, and OutcomeMeasureTitle, plus their description counterparts PrimaryOutcomeDescription, SecondaryOutcomeDescription, OtherOutcomeDescription, OutcomeMeasureDescription, and OutcomeMeasurePopulationDescription — so a term appearing only in outcome prose still matches. Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."

Previous value: -[
-  {
-    "description": "A single phase value.",
-    "type": "string"
-  },
-  {
-    "description": "Multiple phase values (OR).",
-    "items": {
-      "type": "string"
-    },
-    "minItems": 1,
-    "type": "array"
-  }
-]New value: +[
+  {
+    "description": "A single phase value.",
+    "type": "string"
+  },
+  {
+    "description": "Multiple phase values (OR).",
+    "items": {
+      "type": "string"
+    },
+    "type": "array"
+  }
+]

Previous value: -"General free-text search across all fields. Plain words plus AND, OR, NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression — those work here as well as in advancedFilter, so AREA[Phase]PHASE2 is accepted in this parameter; a stray bracket fails. `( )` group sub-expressions and work when matched; `,` acts as AND. The dedicated *Query parameters (conditionQuery, interventionQuery, etc.) scope a search to one field."New value: +"General free-text search across all fields. Runs the 57-field relevance search ClinicalTrials.gov publishes for this parameter — NCTId, NCTIdAlias, OrgStudyId, SecondaryId, Acronym, BriefTitle, OfficialTitle, Condition, InterventionName, InterventionOtherName, Phase, StdAge, StudyType, BriefSummary, outcome measures and their descriptions, LeadSponsorName, CollaboratorName, the Location* fields, the Design* fields, and the ConditionAncestorTerm/InterventionAncestorTerm MeSH umbrellas — so a hit need not carry your term in the field you had in mind. Plain words plus AND, OR, NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression — those work here as well as in advancedFilter, so AREA[Phase]PHASE2 is accepted in this parameter; a stray bracket fails. `( )` group sub-expressions and work when matched; `,` acts as AND. The dedicated *Query parameters (conditionQuery, interventionQuery, etc.) scope a search to one field."

Previous value: -"Sponsor/collaborator name search. Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."New value: +"Sponsor/collaborator name search. Matches LeadSponsorName, CollaboratorName, and OrgFullName. Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."

Previous value: -[
-  {
-    "description": "A single status value.",
-    "type": "string"
-  },
-  {
-    "description": "Multiple status values (OR).",
-    "items": {
-      "type": "string"
-    },
-    "minItems": 1,
-    "type": "array"
-  }
-]New value: +[
+  {
+    "description": "A single status value.",
+    "type": "string"
+  },
+  {
+    "description": "Multiple status values (OR).",
+    "items": {
+      "type": "string"
+    },
+    "type": "array"
+  }
+]

Previous value: -"Search within study titles and acronyms only. Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."New value: +"Search within study titles and acronyms only. Matches Acronym, BriefTitle, and OfficialTitle. Plain words plus AND/OR/NOT. `[ ]` are valid only inside an AREA[FieldName]value or RANGE[min, max] expression, which this parameter accepts; a stray bracket fails. `( )` group sub-expressions when matched; `,` acts as AND."

Previous value: -[
-  {
-    "description": "A single phase value.",
-    "type": "string"
-  },
-  {
-    "description": "Multiple phase values (OR).",
-    "items": {
-      "type": "string"
-    },
-    "type": "array"
-  }
-]New value: +[
+  {
+    "description": "A single phase value.",
+    "type": "string"
+  },
+  {
+    "description": "Multiple phase values (OR).",
+    "items": {
+      "type": "string"
+    },
+    "minItems": 1,
+    "type": "array"
+  }
+]

Previous value: -"Filter by trial phase. Values: EARLY_PHASE1, PHASE1, PHASE2, PHASE3, PHASE4, NA."New value: +"Filter by trial phase. Omit to count all phases — an empty list is rejected, not treated as \"no filter\". Values: EARLY_PHASE1, PHASE1, PHASE2, PHASE3, PHASE4, NA."

Previous value: -[
-  {
-    "description": "A single status value.",
-    "type": "string"
-  },
-  {
-    "description": "Multiple status values (OR).",
-    "items": {
-      "type": "string"
-    },
-    "type": "array"
-  }
-]New value: +[
+  {
+    "description": "A single status value.",
+    "type": "string"
+  },
+  {
+    "description": "Multiple status values (OR).",
+    "items": {
+      "type": "string"
+    },
+    "minItems": 1,
+    "type": "array"
+  }
+]

Previous value: -"Filter by study status. Values: RECRUITING, COMPLETED, ACTIVE_NOT_RECRUITING, NOT_YET_RECRUITING, ENROLLING_BY_INVITATION, SUSPENDED, TERMINATED, WITHDRAWN, UNKNOWN, WITHHELD, NO_LONGER_AVAILABLE, AVAILABLE, APPROVED_FOR_MARKETING, TEMPORARILY_NOT_AVAILABLE."New value: +"Filter by study status. Omit to count all statuses — an empty list is rejected, not treated as \"no filter\". Values: RECRUITING, COMPLETED, ACTIVE_NOT_RECRUITING, NOT_YET_RECRUITING, ENROLLING_BY_INVITATION, SUSPENDED, TERMINATED, WITHDRAWN, UNKNOWN, WITHHELD, NO_LONGER_AVAILABLE, AVAILABLE, APPROVED_FOR_MARKETING, TEMPORARILY_NOT_AVAILABLE."

Previous value: -[
-  {
-    "description": "A single section name.",
-    "enum": [
-      "outcomes",
-      "adverseEvents",
-      "participantFlow",
-      "baseline",
-      "moreInfo"
-    ],
-    "type": "string"
-  },
-  {
-    "description": "Multiple section names.",
-    "items": {
-      "enum": [
-        "outcomes",
-        "adverseEvents",
-        "participantFlow",
-        "baseline",
-        "moreInfo"
-      ],
-      "type": "string"
-    },
-    "type": "array"
-  }
-]New value: +[
+  {
+    "description": "A single section name.",
+    "enum": [
+      "outcomes",
+      "adverseEvents",
+      "participantFlow",
+      "baseline",
+      "moreInfo"
+    ],
+    "type": "string"
+  },
+  {
+    "description": "Multiple section names.",
+    "items": {
+      "enum": [
+        "outcomes",
+        "adverseEvents",
+        "participantFlow",
+        "baseline",
+        "moreInfo"
+      ],
+      "type": "string"
+    },
+    "minItems": 1,
+    "type": "array"
+  }
+]

Previous value: -"Filter which sections to return. Values: outcomes, adverseEvents, participantFlow, baseline, moreInfo. Omit for all sections."New value: +"Filter which sections to return. Values: outcomes, adverseEvents, participantFlow, baseline, moreInfo. Omit for all sections — an empty list is rejected, not treated as omission."

Previous value: -"PascalCase leaf names to return; strongly recommended since full records are ~70KB. Common leaves: NCTId, BriefTitle, BriefSummary, OverallStatus, Phase, LeadSponsorName, Condition. Call clinicaltrials_get_field_definitions with a concept query (e.g., \"adverse events\", \"eligibility\") to find the exact leaf for any concept."New value: +"PascalCase leaf names to return; strongly recommended since full records are ~70KB. Omit for the compact index projection — an empty list is rejected, not treated as omission. Common leaves: NCTId, BriefTitle, BriefSummary, OverallStatus, Phase, LeadSponsorName, Condition. Call clinicaltrials_get_field_definitions with a concept query (e.g., \"adverse events\", \"eligibility\") to find the exact leaf for any concept."

Added value: +1

Previous value: -[
-  {
-    "description": "A single phase value.",
-    "type": "string"
-  },
-  {
-    "description": "Multiple phase values (OR).",
-    "items": {
-      "type": "string"
-    },
-    "type": "array"
-  }
-]New value: +[
+  {
+    "description": "A single phase value.",
+    "type": "string"
+  },
+  {
+    "description": "Multiple phase values (OR).",
+    "items": {
+      "type": "string"
+    },
+    "minItems": 1,
+    "type": "array"
+  }
+]

Previous value: -"Filter by trial phase. Values: EARLY_PHASE1, PHASE1, PHASE2, PHASE3, PHASE4, NA."New value: +"Filter by trial phase. Omit to search all phases — an empty list is rejected, not treated as \"no filter\". Values: EARLY_PHASE1, PHASE1, PHASE2, PHASE3, PHASE4, NA."

Previous value: -[
-  {
-    "description": "A single status value.",
-    "type": "string"
-  },
-  {
-    "description": "Multiple status values (OR).",
-    "items": {
-      "type": "string"
-    },
-    "type": "array"
-  }
-]New value: +[
+  {
+    "description": "A single status value.",
+    "type": "string"
+  },
+  {
+    "description": "Multiple status values (OR).",
+    "items": {
+      "type": "string"
+    },
+    "minItems": 1,
+    "type": "array"
+  }
+]

Previous value: -"Filter by study status. Values: RECRUITING, COMPLETED, ACTIVE_NOT_RECRUITING, NOT_YET_RECRUITING, ENROLLING_BY_INVITATION, SUSPENDED, TERMINATED, WITHDRAWN, UNKNOWN, WITHHELD, NO_LONGER_AVAILABLE, AVAILABLE, APPROVED_FOR_MARKETING, TEMPORARILY_NOT_AVAILABLE."New value: +"Filter by study status. Omit to search all statuses — an empty list is rejected, not treated as \"no filter\". Values: RECRUITING, COMPLETED, ACTIVE_NOT_RECRUITING, NOT_YET_RECRUITING, ENROLLING_BY_INVITATION, SUSPENDED, TERMINATED, WITHDRAWN, UNKNOWN, WITHHELD, NO_LONGER_AVAILABLE, AVAILABLE, APPROVED_FOR_MARKETING, TEMPORARILY_NOT_AVAILABLE."

Previous value: -"Token for the next page. Absent on last page."New value: +"Token for the next page. Absent when this response already carries every matching study; otherwise it mirrors the upstream cursor, which ClinicalTrials.gov emits whenever a page fills to pageSize — so on a continuation page a token can still lead to an empty page."

Previous value: -"Return condensed summaries instead of full data. Reduces payload from ~200KB to ~5KB per study. Summaries include outcome titles, types, timeframes, group counts, and top-level stats — omitting individual measurements, analyses, and per-group data."New value: +"Return condensed summaries instead of full data. Full mode renders every row and field on both output channels, so a large results set can exceed 500KB per study; summary mode reduces that to ~5KB. Summaries include outcome titles, types, timeframes, group counts, and top-level stats — omitting individual measurements, analyses, and per-group data."