giip
SES Proposal
AI OperationsLow自動化障害対応

A guard that detects contamination in AI-generated content, and an operating rule that never treats regeneration alone as "done"

Published 2026-08-16 · Updated 2026-08-16 · Last Verified 2026-08-16

Answer

AI content generated unattended — for example by a scheduler — can end up "contaminated" with boilerplate refusal/apology text, text cut off mid-generation, or fragments of a prompt or instruction. None of this raises an error; processing completes normally, so nobody notices until a human reads the body directly. The effective countermeasure is to mechanically scan for known patterns and block delivery/storage before it happens, trigger an automatic regeneration, and only mark the job "done" after directly checking the regenerated output — never treat "it regenerated" by itself as the completion condition.

Applicability of This Document

ProductAI-generated reports and automatically generated content in general
Verified VersionsNot applicable (a design pattern applicable to any text-generation pipeline that goes through an LLM API)
EnvironmentScheduler-driven batch generation, AI operations pipelines on AWS/Azure
Required PermissionsRead access to the generation pipeline's output files/logs (changing the pipeline to add the guard requires pipeline-edit permission)
Execution ImpactThe contamination scan itself is read-only. Automatic regeneration triggered by the guard does re-run the pipeline
RestartNot required
Last Verified2026-08-16

Ready-to-Run Commands

Scan generated output for known contamination patterns (read-only)Read-only
対象
Output files/logs of the text-generation pipeline
権限
Read access to the output files
変更作業
None (read-only)
Production実行
Safe
# 対象: テキスト生成パイプラインの出力ファイル・ログ
# 権限: 出力ファイルの読み取り権限
# 変更作業: なし(参照のみ)
# Production実行: 可能
#
# 既知の拒否・謝罪定型文、指示文の漏れ込みを出力テキストからスキャンする(例)
grep -RniE "(申し訳ございません|as an ai|以下の指示に従って|I cannot fulfill)" ./generated-output/

# 期待される末尾構造(結語・フッタ等)が欠けている=途中切断の疑いがあるファイルを洗い出す
for f in ./generated-output/*.md; do
  tail -c 200 "$f" | grep -q "《期待する末尾の文言》" || echo "TRUNCATION SUSPECT: $f"
done

The regexes/patterns vary by environment. Detection here is only meant to narrow down what needs pre-delivery review — it is not a definitive list covering every contamination pattern. Treat this as a living set you add to whenever a new pattern is found.

Wire in a detect → auto-regenerate → check-the-body gate (requires a pipeline change)Low
対象
The gate inserted between generation and delivery
権限
Permission to edit the generation pipeline's configuration/code
変更作業
Yes (adds a validation step before delivery, and triggers regeneration on failure)
Production実行
Safe (once a cap is set on automatic-regeneration attempts)
# 対象: 生成→配信の間に挟むゲート処理
# 権限: 生成パイプラインの設定・コード変更権限
# 変更作業: あり(配信前に検証ステップを追加し、失敗時は再生成をトリガーする)
# Production実行: 可能(自動再生成の上限回数を設定した上で)
#
# 1. 生成が終わったら、配信・保存の前に既知パターンのスキャンを実行する
# 2. 検出されたら配信をブロックし、プロンプトを調整して再生成する(上限N回)
# 3. 上限に達しても解消しない場合は人間のレビューに回す(自動配信しない)
# 4. 再生成が成功した場合も、処理ログの成功だけで完了と判断せず、
#    出力された本文を直接確認してから完了とする(ここが最も見落とされやすい)

The key is never skipping step 4. "The regeneration completed successfully" (the log) and "the body is actually correct" (the text) are two different things — the latter can only be known by checking directly.

How to Read the Results

ColumnMeaningWhat to Check
Boilerplate apology/refusal textA trace of the model failing to complete the instructionWhether phrases like "I'm sorry" are mixed into the body
Body cut off mid-generationGeneration ended due to a length limit or interruptionWhether the expected closing structure (sign-off, footer, etc.) is missing
Leaked meta-instructionsA fragment of the prompt or system instruction leaking straight into the outputWhether any instruction text not meant for the reader is present
Mixed-language contaminationText in a language other than the intended one slipping inWhether the proportion of unexpected character types exceeds a threshold

When to Use This

  • Scheduled reports sometimes contain text not meant for the reader — apology boilerplate, fragments of instructions
  • Generation sometimes gets delivered/stored while cut off mid-way
  • Regenerating the same section sometimes fixes it, sometimes does not
  • Nobody notices the contamination until a human reads the body directly

Possible Causes (Most Likely First)

  1. 01

    The assumption that "regenerating fixes it" was operated on without ever being verified

    The regenerated output was never checked directly — only whether processing completed normally was checked, and that was treated as "done." In reality the same contamination pattern can recur, or a different one can appear.

  2. 02

    There was no mechanical check between generation and delivery

    The LLM's output was always treated as well-formed, correct text and delivered/stored as-is.

  3. 03

    Contamination patterns are not uniform

    Refusal text, mid-generation cutoffs, leaked instructions, mixed-language contamination — there are multiple distinct types, and no single simple check covers them all.

  4. 04

    With unattended scheduled execution, no human is present to notice anomalies

    Periodic batch jobs are not watched by a human right after they run, so the structure itself guarantees the problem is noticed only later.

Diagnostic Steps

  1. 1

    Compile the known contamination patterns

    Read-only

    Gather real past examples of refusal text, mid-generation cutoffs, leaked instructions, and mixed-language contamination as the basis for detection rules.

  2. 2

    Check whether scanning is feasible right after generation, before delivery

    Read-only

    Since noticing after delivery means more rework, check where in the pipeline a check can be inserted.

  3. 3

    Check whether the operation actually reads the body directly after regeneration

    Read-only

    "It re-ran" and "it's fixed" are different things. Check whether the procedure looks at the actual text, not just the processing log.

Solutions

Low-risk action that can be done immediately

  • Add one detection rule for known patterns

    Low

    Even if not exhaustive, make at least the known refusal-text and mid-cutoff patterns mechanically detectable first.

  • Make "read the body directly after regeneration" an operating rule

    Low

    Do not treat "it re-ran" as the completion condition. Only mark it done after checking the actual output text.

Change requiring advance review

  • Insert a gate between generate → validate → deliver

    Medium

    When a detection rule fires, block delivery, auto-regenerate up to a cap, and route to human review if it still fails after hitting the cap.

  • Operate the detection rules as a living list

    Low

    Add a rule whenever a new contamination pattern is found, and roll it out to other generation pipelines as well.

Work requiring expert review

  • Continuously monitor the guard's trigger rate as a quality signal

    Expert Review Required

    A rising trigger rate can indicate a regression upstream, in the model or the prompt. Build a way to track the trend over time.

!Warnings

  • Do not adopt the assumption that "regenerating fixes it" without verification. Whether it actually got fixed can only be known by checking the output directly.
  • A guard cannot anticipate every contamination pattern in advance. Operate on the assumption that you add a rule each time a new pattern is found.
  • Without a cap on automatic-regeneration attempts, a job that keeps failing will retry endlessly.
  • Contamination noticed after delivery may already have reached readers. It is preferable to detect it before delivery.

Differences by Version and Environment

Model/provider independentThis guard pattern does not depend on any specific LLM provider or model. When you change the prompt or model, re-check whether the known-pattern list is still valid.

If This Doesn't Resolve It

  • Look back at recent "resolved" calls and check whether they actually involved checking the output

    Check for cases where something was marked done based only on a successful processing log.

  • Check whether the same guard exists on other generation pipelines

    A problem found in one pipeline is likely to be common to similar generation processes elsewhere.

  • Check whether the guard's trigger rate can be tracked over time

    If it cannot be tracked, you will be slow to notice a regression in the model or prompt.

Basis and Limitations of This Document

Content verified through real-world operations

This contamination-detection and regeneration guard is a design pattern generalized from cases observed in the operation of an actual periodic report-generation pipeline. Figures on how comprehensive the detectable contamination patterns are, or how often they occur, are not stated because they are environment-dependent.

FAQ

Can contamination in AI-generated content be fully detected automatically?

No. Detection of known patterns can be mechanized, but an unknown pattern slips through if it is not already in the detection rules. Pair automated detection with directly checking the body after regeneration.

Does regenerating fix the contamination?

Sometimes, but not always. Do not treat "it was regenerated" as the completion condition — judge completion only after checking the actual output.

Is this guard specific to one LLM provider?

No. It is designed to not depend on any specific provider or model. That said, re-check whether the known-pattern list is still valid whenever you change the model or prompt.

Should every generation pipeline adopt this?

If it runs unattended on a schedule and no human watches the output right after generation, it should be a high priority. A contamination pattern found in one pipeline is often common to other similar generation processes as well.

Questions This Document Covers

  • How to guarantee the quality of automatically generated AI reports
  • How to deal with instruction fragments leaking into LLM output

What the Risk Labels Mean

  • Read-onlyDoes not change data or settings.
  • LowImpact is limited, but permissions and load should be checked.
  • MediumMay affect performance, locking, or cost.
  • HighMay cause an outage, data loss, or require recovery work.
  • Expert Review RequiredRequires a separate review before applying to production.

GIIP's Scope of Support

For periodically generated reports and other AI-generated content, GIIP runs a check before delivery that detects known contamination patterns; when one fires, it triggers automatic regeneration and only marks the job done after directly checking the regenerated body. The policy is to include this check by default whenever a similar generation pipeline is newly built.

Author & Technical Review

GIIP Production Operations Team

About 30 years of experience in designing, migrating, and operating large-scale web services, SQL Server, Oracle, AWS, and Azure. Experience includes 12 sets of x12large-class AWS RDS for SQL Server environments, an Oracle environment with roughly 120,000 tables, and migrating roughly 3TB from TiDB to Aurora MySQL. AI agents and human experts currently continue to monitor and operate multiple cloud databases and about 30 web services.

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