Caption File Check

Preflight one caption or subtitle file before delivery. Attach a WebVTT (.vtt), SRT (.srt), or TTML/IMSC (.ttml/.xml) caption file in chat or give a publicly fetchable URL and it downloads the artifact under an SSRF-guarded, 2 MB-capped fetch, detects the format by content and the byte encoding and BOM, then parses it with the real spec engine (the WebVTT spec parser, a dedicated SRT parser, or the imscJS TTML/IMSC profile engine) and returns deterministic evidence: pass/fail, cue count, structural spec and IMSC profile-conformance errors, overlapping / negative / out-of-order / empty cues, per-line length, and per-cue and summary reading speed (CPS) against a named platform profile (netflix-adult-20, netflix-children-17, youtube, ebu-tt). It reports only source-file conformance, timing, encoding, and reading-speed facts against a dated profile. It does not judge translation quality, transcription accuracy, or synchronization against the video. An arbitrary XML or text file that is not a caption track returns an explicit unsupported-format error. Fetching and parsing a full-length track can take up to 60 seconds. WebVTT limitation: the parser drops payload-less cues; cue counts, indices, timing checks and comparisons cover retained cues only, not those omitted cues.

{
  "type": "object",
  "properties": {
    "url": {
      "minLength": 1,
      "maxLength": 2048,
      "pattern": "^https?://",
      "type": "string",
      "description": "A publicly fetchable HTTP(S) URL of a WebVTT, SRT, or TTML/IMSC caption file, detected by content not extension. Provide either this or an attached file, never both. Query strings are allowed but never logged. Pasted caption bodies, data URLs, FTP/SFTP, and URLs needing credentials, headers, or cookies are not supported.\n\nSTRICT RULE: Caption check failed — provide either a caption URL or an attached caption file, not both\nSTRICT RULE: Caption check failed — provide a public caption URL or attach the caption file"
    },
    "file": {
      "type": "object",
      "required": [
        "download_url",
        "file_id"
      ],
      "properties": {
        "download_url": {
          "type": "string",
          "description": "Temporary authorized download URL supplied by ChatGPT; fetch it only while handling this tool call"
        },
        "file_id": {
          "type": "string",
          "description": "ChatGPT file id for the attached file"
        },
        "mime_type": {
          "type": "string",
          "description": "MIME type when ChatGPT knows it"
        },
        "file_name": {
          "type": "string",
          "description": "Original file name when ChatGPT knows it"
        }
      },
      "description": "A caption file attached in chat (WebVTT, SRT, or TTML/IMSC), detected by content not extension. Provide either this or url, never both.",
      "additionalProperties": false
    },
    "profile": {
      "anyOf": [
        {
          "const": "netflix-adult-20",
          "type": "string",
          "description": "Named reading-speed profile to judge CPS and line length against. netflix-adult-20 (default, 20 CPS) and netflix-children-17 (17 CPS) are spec-backed; youtube and ebu-tt are advisory ~17 CPS heuristics."
        },
        {
          "const": "netflix-children-17",
          "type": "string",
          "description": "Named reading-speed profile to judge CPS and line length against. netflix-adult-20 (default, 20 CPS) and netflix-children-17 (17 CPS) are spec-backed; youtube and ebu-tt are advisory ~17 CPS heuristics."
        },
        {
          "const": "youtube",
          "type": "string",
          "description": "Named reading-speed profile to judge CPS and line length against. netflix-adult-20 (default, 20 CPS) and netflix-children-17 (17 CPS) are spec-backed; youtube and ebu-tt are advisory ~17 CPS heuristics."
        },
        {
          "const": "ebu-tt",
          "type": "string",
          "description": "Named reading-speed profile to judge CPS and line length against. netflix-adult-20 (default, 20 CPS) and netflix-children-17 (17 CPS) are spec-backed; youtube and ebu-tt are advisory ~17 CPS heuristics."
        }
      ],
      "description": "Named reading-speed profile to judge CPS and line length against. netflix-adult-20 (default, 20 CPS) and netflix-children-17 (17 CPS) are spec-backed; youtube and ebu-tt are advisory ~17 CPS heuristics."
    }
  },
  "additionalProperties": false
}

{
  "type": "object",
  "properties": {
    "url": {
      "type": "string",
      "description": "The checked caption source: the submitted URL query- and fragment-stripped, or the attached file's name"
    },
    "checkedAt": {
      "type": "string",
      "description": "ISO timestamp when the caption result was produced"
    },
    "detectedFormat": {
      "type": "string",
      "description": "webvtt, srt, or ttml (covers IMSC), detected by content"
    },
    "ttmlProfile": {
      "type": "string",
      "description": "IMSC/TTML profile designator declared in the file, when present"
    },
    "encoding": {
      "type": "string",
      "description": "Detected byte encoding of the caption file"
    },
    "bom": {
      "type": "string",
      "description": "Byte-order-mark detected: utf-8, utf-16le, utf-16be, or none"
    },
    "pass": {
      "type": "boolean",
      "description": "True when the file passes all checked format, timing, line-length and reading-speed criteria for the selected profile. False can include an advisory readability threshold breach, not just a specification error; this is not a platform-acceptance verdict"
    },
    "cueCount": {
      "type": "number",
      "description": "Number of caption cues retained for checking; payload-less WebVTT cues are omitted by the parser"
    },
    "rawCueCount": {
      "type": "number",
      "description": "Cues parsed before the 20,000-cue cap; excludes payload-less WebVTT cues dropped by the parser"
    },
    "profile": {
      "type": "object",
      "required": [
        "id",
        "date",
        "label",
        "maxCps",
        "maxLineLength",
        "advisory",
        "source"
      ],
      "properties": {
        "id": {
          "type": "string",
          "description": "Identifier of the applied caption profile"
        },
        "date": {
          "type": "string",
          "description": "Review month recorded for the profile"
        },
        "label": {
          "type": "string",
          "description": "Display name of the applied caption profile"
        },
        "maxCps": {
          "type": "number",
          "description": "Maximum characters per second specified by the profile"
        },
        "maxLineLength": {
          "type": "number",
          "description": "Maximum characters per line specified by the profile"
        },
        "advisory": {
          "type": "boolean",
          "description": "The reading-speed limit is an industry heuristic, not a spec-mandated number"
        },
        "source": {
          "type": "string",
          "description": "Source or advisory basis recorded for the profile"
        }
      },
      "description": "Reading-speed and line-length profile applied to the caption checks",
      "additionalProperties": false
    },
    "timing": {
      "type": "object",
      "required": [
        "checked",
        "clean",
        "overlapping",
        "negative",
        "outOfOrder",
        "empty"
      ],
      "properties": {
        "checked": {
          "type": "boolean",
          "description": "Cue timing could be analysed (at least one cue)"
        },
        "clean": {
          "type": "boolean",
          "description": "Checked and no overlapping, negative, out-of-order, or empty retained cue found, distinguished from not-checked; omitted payload-less WebVTT cues are not assessed"
        },
        "overlapping": {
          "type": "array",
          "items": {
            "type": "object",
            "required": [
              "cue",
              "previousCue"
            ],
            "properties": {
              "cue": {
                "type": "number",
                "description": "Index of the affected caption cue"
              },
              "previousCue": {
                "type": "number",
                "description": "Index of the preceding overlapping cue"
              }
            },
            "additionalProperties": false
          },
          "description": "Cues that start before the preceding cue ends"
        },
        "negative": {
          "type": "array",
          "items": {
            "type": "object",
            "required": [
              "cue",
              "durationMs"
            ],
            "properties": {
              "cue": {
                "type": "number",
                "description": "Index of the affected caption cue"
              },
              "durationMs": {
                "type": "number",
                "description": "Cue end time minus start time in milliseconds"
              }
            },
            "additionalProperties": false
          },
          "description": "Cues whose end time is at or before their start time"
        },
        "outOfOrder": {
          "type": "array",
          "items": {
            "type": "object",
            "required": [
              "cue"
            ],
            "properties": {
              "cue": {
                "type": "number",
                "description": "Index of the affected caption cue"
              }
            },
            "additionalProperties": false
          },
          "description": "Cues that start before the preceding cue starts"
        },
        "empty": {
          "type": "array",
          "items": {
            "type": "object",
            "required": [
              "cue"
            ],
            "properties": {
              "cue": {
                "type": "number",
                "description": "Index of the affected caption cue"
              }
            },
            "additionalProperties": false
          },
          "description": "Cues whose text is empty after trimming whitespace"
        }
      },
      "description": "Measured retained-cue timing and empty-text findings; WebVTT indices refer to retained cues, not original source positions",
      "additionalProperties": false
    },
    "lineLength": {
      "type": "object",
      "required": [
        "limit",
        "maxObserved",
        "overLimit"
      ],
      "properties": {
        "limit": {
          "type": "number",
          "description": "Profile maximum characters per line"
        },
        "maxObserved": {
          "type": "number",
          "description": "Largest character count observed on a caption line"
        },
        "overLimit": {
          "type": "array",
          "items": {
            "type": "object",
            "required": [
              "cue",
              "line",
              "length"
            ],
            "properties": {
              "cue": {
                "type": "number",
                "description": "Index of the affected caption cue"
              },
              "line": {
                "type": "number",
                "description": "One-based line number within the cue"
              },
              "length": {
                "type": "number",
                "description": "Number of Unicode characters on the affected line"
              }
            },
            "additionalProperties": false
          },
          "description": "Caption lines exceeding the profile character limit"
        }
      },
      "description": "Per-line character counts checked against the profile limit",
      "additionalProperties": false
    },
    "cps": {
      "type": "object",
      "required": [
        "profileId",
        "limit",
        "advisory",
        "measured",
        "max",
        "mean",
        "breaches"
      ],
      "properties": {
        "profileId": {
          "type": "string",
          "description": "Identifier of the profile supplying the reading-speed limit"
        },
        "limit": {
          "type": "number",
          "description": "Profile maximum characters per second"
        },
        "advisory": {
          "type": "boolean",
          "description": "Whether the profile reading-speed limit is advisory"
        },
        "measured": {
          "type": "boolean",
          "description": "At least one cue had positive duration and text, distinguished from not-measured"
        },
        "max": {
          "type": "number",
          "description": "Highest per-cue characters-per-second"
        },
        "mean": {
          "type": "number",
          "description": "Mean characters per second across measured nonempty cues with positive duration"
        },
        "breaches": {
          "type": "array",
          "items": {
            "type": "object",
            "required": [
              "cue",
              "cps"
            ],
            "properties": {
              "cue": {
                "type": "number",
                "description": "Index of the affected caption cue"
              },
              "cps": {
                "type": "number",
                "description": "Measured reading speed for the cue in characters per second"
              }
            },
            "additionalProperties": false
          },
          "description": "Cues whose reading speed exceeds the profile limit"
        }
      },
      "description": "Per-cue and summary reading-speed measurements",
      "additionalProperties": false
    },
    "structuralErrors": {
      "type": "array",
      "items": {
        "type": "object",
        "required": [
          "severity",
          "code",
          "message"
        ],
        "properties": {
          "severity": {
            "type": "string",
            "description": "Severity assigned by the caption parser"
          },
          "code": {
            "type": "string",
            "description": "Machine-readable structural finding code"
          },
          "message": {
            "type": "string",
            "description": "Parser diagnostic describing the structural finding"
          },
          "cue": {
            "type": "number",
            "description": "Index of the affected caption cue"
          }
        },
        "additionalProperties": false
      },
      "description": "Spec-parser and IMSC/TTML profile-conformance findings"
    },
    "structuralErrorCounts": {
      "type": "object",
      "required": [
        "error",
        "warning"
      ],
      "properties": {
        "error": {
          "type": "number",
          "description": "Number of error-severity structural findings"
        },
        "warning": {
          "type": "number",
          "description": "Number of warning-severity structural findings"
        }
      },
      "description": "Counts of structural findings grouped by severity",
      "additionalProperties": false
    },
    "specUsed": {
      "type": "string",
      "description": "The dated spec identifier the detected format was checked against"
    },
    "truncation": {
      "type": "array",
      "items": {
        "type": "string",
        "description": "Machine-checkable truncation markers, e.g. cue-cap"
      },
      "description": "Markers identifying checks truncated by configured limits"
    }
  },
  "required": [
    "url",
    "checkedAt",
    "detectedFormat",
    "encoding",
    "bom",
    "pass",
    "cueCount",
    "rawCueCount",
    "profile",
    "timing",
    "lineLength",
    "cps",
    "structuralErrors",
    "structuralErrorCounts",
    "specUsed",
    "truncation"
  ],
  "additionalProperties": false
}

Compare exactly two caption or subtitle files under identical bounded checks: an original versus its translated track, before versus after a timing fix, or a format migration. Attach two WebVTT, SRT, or TTML/IMSC caption files in chat or give two publicly fetchable URLs and it runs the same SSRF-guarded, 2 MB-capped preflight as caption_check on each, then aligns them by cue index and reports side-by-side pass status, detected-format and encoding differences, the cue-count delta, timing drift and overlap differences, reading-speed (CPS) regressions, structural-error deltas, and a winner only when the measured checks separate the two. Use caption_check for a single file. It reports only source-file conformance, timing, encoding, and reading-speed facts against a dated profile: never translation quality, transcription accuracy, or sync against the video. Fetching and parsing two live files can take up to 60 seconds. WebVTT limitation: the parser drops payload-less cues; cue counts, indices, timing checks and comparisons cover retained cues only, not those omitted cues.

{
  "type": "object",
  "properties": {
    "urls": {
      "minItems": 2,
      "maxItems": 2,
      "type": "array",
      "items": {
        "minLength": 1,
        "maxLength": 2048,
        "pattern": "^https?://",
        "type": "string",
        "description": "A publicly fetchable HTTP(S) WebVTT, SRT, or TTML/IMSC caption URL, detected by content."
      },
      "description": "Exactly two public caption URLs to compare, in the order they should appear side by side (for example original then translated). Provide either this or files, never both.\n\nSTRICT RULE: Caption compare failed — provide either two caption URLs or two attached caption files, not both\nSTRICT RULE: Caption compare failed — provide two public caption URLs or attach two caption files"
    },
    "files": {
      "minItems": 2,
      "maxItems": 2,
      "type": "array",
      "items": {
        "type": "object",
        "required": [
          "download_url",
          "file_id"
        ],
        "properties": {
          "download_url": {
            "type": "string",
            "description": "Temporary authorized download URL supplied by ChatGPT; fetch it only while handling this tool call"
          },
          "file_id": {
            "type": "string",
            "description": "ChatGPT file id for the attached file"
          },
          "mime_type": {
            "type": "string",
            "description": "MIME type when ChatGPT knows it"
          },
          "file_name": {
            "type": "string",
            "description": "Original file name when ChatGPT knows it"
          }
        },
        "description": "A caption file attached in chat (WebVTT, SRT, or TTML/IMSC), detected by content.",
        "additionalProperties": false
      },
      "description": "Exactly two caption files attached in chat to compare, in the order they should appear side by side (for example original then translated). Provide either this or urls, never both."
    },
    "profile": {
      "anyOf": [
        {
          "const": "netflix-adult-20",
          "type": "string",
          "description": "Named reading-speed profile applied to both tracks. netflix-adult-20 (default), netflix-children-17, youtube, ebu-tt."
        },
        {
          "const": "netflix-children-17",
          "type": "string",
          "description": "Named reading-speed profile applied to both tracks. netflix-adult-20 (default), netflix-children-17, youtube, ebu-tt."
        },
        {
          "const": "youtube",
          "type": "string",
          "description": "Named reading-speed profile applied to both tracks. netflix-adult-20 (default), netflix-children-17, youtube, ebu-tt."
        },
        {
          "const": "ebu-tt",
          "type": "string",
          "description": "Named reading-speed profile applied to both tracks. netflix-adult-20 (default), netflix-children-17, youtube, ebu-tt."
        }
      ],
      "description": "Named reading-speed profile applied to both tracks. netflix-adult-20 (default), netflix-children-17, youtube, ebu-tt."
    }
  },
  "description": "STRICT RULE: Caption compare failed — the two caption files are the same; provide two distinct caption files.",
  "additionalProperties": false
}

{
  "type": "object",
  "properties": {
    "checkedAt": {
      "type": "string",
      "description": "ISO timestamp when the caption result was produced"
    },
    "profile": {
      "type": "object",
      "required": [
        "id",
        "date",
        "label",
        "maxCps",
        "maxLineLength",
        "advisory",
        "source"
      ],
      "properties": {
        "id": {
          "type": "string",
          "description": "Identifier of the applied caption profile"
        },
        "date": {
          "type": "string",
          "description": "Review month recorded for the profile"
        },
        "label": {
          "type": "string",
          "description": "Display name of the applied caption profile"
        },
        "maxCps": {
          "type": "number",
          "description": "Maximum characters per second specified by the profile"
        },
        "maxLineLength": {
          "type": "number",
          "description": "Maximum characters per line specified by the profile"
        },
        "advisory": {
          "type": "boolean",
          "description": "The reading-speed limit is an industry heuristic, not a spec-mandated number"
        },
        "source": {
          "type": "string",
          "description": "Source or advisory basis recorded for the profile"
        }
      },
      "description": "Reading-speed and line-length profile applied to the caption checks",
      "additionalProperties": false
    },
    "tracks": {
      "type": "array",
      "items": {
        "type": "object",
        "required": [
          "url",
          "ok"
        ],
        "properties": {
          "url": {
            "type": "string",
            "description": "The checked caption source: the submitted URL query- and fragment-stripped, or the attached file's name"
          },
          "ok": {
            "type": "boolean",
            "description": "Whether the caption file could be fetched and preflighted"
          },
          "failed": {
            "type": "string",
            "description": "Reason the caption file could not be preflighted"
          },
          "detectedFormat": {
            "type": "string",
            "description": "Caption format detected from file content"
          },
          "encoding": {
            "type": "string",
            "description": "Detected byte encoding of the caption file"
          },
          "bom": {
            "type": "string",
            "description": "Detected byte-order mark, or none"
          },
          "pass": {
            "type": "boolean",
            "description": "Whether the track passes structural, timing, line-length, and reading-speed checks"
          },
          "cueCount": {
            "type": "number",
            "description": "Number of caption cues retained for checking"
          },
          "timing": {
            "type": "object",
            "required": [
              "checked",
              "clean",
              "overlapping",
              "negative",
              "outOfOrder",
              "empty"
            ],
            "properties": {
              "checked": {
                "type": "boolean",
                "description": "Cue timing could be analysed (at least one cue)"
              },
              "clean": {
                "type": "boolean",
                "description": "Checked and no overlapping, negative, out-of-order, or empty cue found, distinguished from not-checked"
              },
              "overlapping": {
                "type": "array",
                "items": {
                  "type": "object",
                  "required": [
                    "cue",
                    "previousCue"
                  ],
                  "properties": {
                    "cue": {
                      "type": "number",
                      "description": "Index of the affected caption cue"
                    },
                    "previousCue": {
                      "type": "number",
                      "description": "Index of the preceding overlapping cue"
                    }
                  },
                  "additionalProperties": false
                },
                "description": "Cues that start before the preceding cue ends"
              },
              "negative": {
                "type": "array",
                "items": {
                  "type": "object",
                  "required": [
                    "cue",
                    "durationMs"
                  ],
                  "properties": {
                    "cue": {
                      "type": "number",
                      "description": "Index of the affected caption cue"
                    },
                    "durationMs": {
                      "type": "number",
                      "description": "Cue end time minus start time in milliseconds"
                    }
                  },
                  "additionalProperties": false
                },
                "description": "Cues whose end time is at or before their start time"
              },
              "outOfOrder": {
                "type": "array",
                "items": {
                  "type": "object",
                  "required": [
                    "cue"
                  ],
                  "properties": {
                    "cue": {
                      "type": "number",
                      "description": "Index of the affected caption cue"
                    }
                  },
                  "additionalProperties": false
                },
                "description": "Cues that start before the preceding cue starts"
              },
              "empty": {
                "type": "array",
                "items": {
                  "type": "object",
                  "required": [
                    "cue"
                  ],
                  "properties": {
                    "cue": {
                      "type": "number",
                      "description": "Index of the affected caption cue"
                    }
                  },
                  "additionalProperties": false
                },
                "description": "Cues whose text is empty after trimming whitespace"
              }
            },
            "description": "Measured cue timing and empty-text findings",
            "additionalProperties": false
          },
          "lineLength": {
            "type": "object",
            "required": [
              "limit",
              "maxObserved",
              "overLimit"
            ],
            "properties": {
              "limit": {
                "type": "number",
                "description": "Profile maximum characters per line"
              },
              "maxObserved": {
                "type": "number",
                "description": "Largest character count observed on a caption line"
              },
              "overLimit": {
                "type": "array",
                "items": {
                  "type": "object",
                  "required": [
                    "cue",
                    "line",
                    "length"
                  ],
                  "properties": {
                    "cue": {
                      "type": "number",
                      "description": "Index of the affected caption cue"
                    },
                    "line": {
                      "type": "number",
                      "description": "One-based line number within the cue"
                    },
                    "length": {
                      "type": "number",
                      "description": "Number of Unicode characters on the affected line"
                    }
                  },
                  "additionalProperties": false
                },
                "description": "Caption lines exceeding the profile character limit"
              }
            },
            "description": "Per-line character counts checked against the profile limit",
            "additionalProperties": false
          },
          "cps": {
            "type": "object",
            "required": [
              "profileId",
              "limit",
              "advisory",
              "measured",
              "max",
              "mean",
              "breaches"
            ],
            "properties": {
              "profileId": {
                "type": "string",
                "description": "Identifier of the profile supplying the reading-speed limit"
              },
              "limit": {
                "type": "number",
                "description": "Profile maximum characters per second"
              },
              "advisory": {
                "type": "boolean",
                "description": "Whether the profile reading-speed limit is advisory"
              },
              "measured": {
                "type": "boolean",
                "description": "At least one cue had positive duration and text, distinguished from not-measured"
              },
              "max": {
                "type": "number",
                "description": "Highest per-cue characters-per-second"
              },
              "mean": {
                "type": "number",
                "description": "Mean characters per second across measured nonempty cues with positive duration"
              },
              "breaches": {
                "type": "array",
                "items": {
                  "type": "object",
                  "required": [
                    "cue",
                    "cps"
                  ],
                  "properties": {
                    "cue": {
                      "type": "number",
                      "description": "Index of the affected caption cue"
                    },
                    "cps": {
                      "type": "number",
                      "description": "Measured reading speed for the cue in characters per second"
                    }
                  },
                  "additionalProperties": false
                },
                "description": "Cues whose reading speed exceeds the profile limit"
              }
            },
            "description": "Per-cue and summary reading-speed measurements",
            "additionalProperties": false
          },
          "structuralErrorCounts": {
            "type": "object",
            "required": [
              "error",
              "warning"
            ],
            "properties": {
              "error": {
                "type": "number",
                "description": "Number of error-severity structural findings"
              },
              "warning": {
                "type": "number",
                "description": "Number of warning-severity structural findings"
              }
            },
            "description": "Counts of structural findings grouped by severity",
            "additionalProperties": false
          }
        },
        "additionalProperties": false
      },
      "description": "The two tracks in input order"
    },
    "comparison": {
      "type": "object",
      "required": [
        "cueCountDelta",
        "formatDiffers",
        "encodingDiffers",
        "passDiffers",
        "timingDrift",
        "overlapDelta",
        "cpsRegression",
        "structuralErrorDelta"
      ],
      "properties": {
        "cueCountDelta": {
          "type": "number",
          "description": "Second track cue count minus first"
        },
        "formatDiffers": {
          "type": "boolean",
          "description": "Whether the detected caption formats differ"
        },
        "encodingDiffers": {
          "type": "boolean",
          "description": "Whether the detected byte encodings differ"
        },
        "passDiffers": {
          "type": "boolean",
          "description": "Whether the two caption pass results differ"
        },
        "timingDrift": {
          "type": "object",
          "required": [
            "alignedCues",
            "maxStartDriftMs",
            "meanStartDriftMs",
            "driftingCues"
          ],
          "properties": {
            "alignedCues": {
              "type": "number",
              "description": "Cue positions compared by index, min of the two counts"
            },
            "maxStartDriftMs": {
              "type": "number",
              "description": "Largest absolute cue-start drift in milliseconds"
            },
            "meanStartDriftMs": {
              "type": "number",
              "description": "Mean absolute cue-start drift in milliseconds"
            },
            "driftingCues": {
              "type": "number",
              "description": "Aligned positions whose start times differ by more than 500 ms"
            }
          },
          "description": "Absolute cue-start drift across positions aligned by cue index",
          "additionalProperties": false
        },
        "overlapDelta": {
          "type": "number",
          "description": "Second track overlapping-cue count minus first"
        },
        "cpsRegression": {
          "type": "object",
          "required": [
            "firstMax",
            "secondMax",
            "delta"
          ],
          "properties": {
            "firstMax": {
              "type": "number",
              "description": "Maximum reading speed of the first track in characters per second"
            },
            "secondMax": {
              "type": "number",
              "description": "Maximum reading speed of the second track in characters per second"
            },
            "delta": {
              "type": "number",
              "description": "Second track max CPS minus first: positive means the second reads faster"
            }
          },
          "description": "Change in maximum reading speed from the first track to the second",
          "additionalProperties": false
        },
        "structuralErrorDelta": {
          "type": "object",
          "required": [
            "error",
            "warning"
          ],
          "properties": {
            "error": {
              "type": "number",
              "description": "Second-track structural error count minus first-track count"
            },
            "warning": {
              "type": "number",
              "description": "Second-track structural warning count minus first-track count"
            }
          },
          "description": "Second-track structural finding counts minus first-track counts",
          "additionalProperties": false
        }
      },
      "description": "Measured differences between the two successfully preflighted tracks",
      "additionalProperties": false
    },
    "winner": {
      "type": "object",
      "required": [
        "url",
        "reason"
      ],
      "properties": {
        "url": {
          "type": "string",
          "description": "Reported source identifier of the track with fewer measured problems"
        },
        "reason": {
          "type": "string",
          "description": "Measured findings supporting the fewer-problems track"
        }
      },
      "description": "Track with fewer weighted structural, timing, reading-speed, and line-length problems",
      "additionalProperties": false
    },
    "notes": {
      "type": "array",
      "items": {
        "type": "string"
      },
      "description": "Notes about incomplete checks or completion under identical limits"
    }
  },
  "required": [
    "checkedAt",
    "profile",
    "tracks",
    "notes"
  ],
  "additionalProperties": false
}