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tim-osterhustim-osterhus/millrace-skills/skills/generate-synthetic-data/SKILL.md

generate-synthetic-data

Skill0 starsChanged 7 months agoApache-2.0View on GitHub

Guardrail for generating synthetic datasets from observed failure modes, seed examples, schemas, quality filters, and diversity requirements.

4 other projects use a version of this.

Adopted by

Most recently taken up by

The file

We split this skill into the rules it gives an agent

10 rules. 0 are common, 10 are distinctive, and 0 are very specific to this project.

  • 0

    Common

    Most of the 4 edited versions we read keep these.

  • 10

    Distinctive

    This author's own choices. Worth a look.

  • 0

    Very specific

    Tied to their project's names, files or tools. Probably skip.

  • Common
  • Distinctive
  • Very specific
  1. Distinctive:

    Start from real traces, observed failures, seed examples, or source documents.

    line 29
  2. Distinctive:

    Keep provenance and prompt/config records.

    line 33
  3. Distinctive:

    Do not use synthetic data as a substitute for real traces when real traces exist.

    line 37
  4. Distinctive:

    Do not generate unsupported facts or private personal details.

    line 38
  5. Distinctive:

    Do not mix synthetic training rows into eval sets without clear split separation.

    line 39
  6. Distinctive:

    Treat LLM-generated labels as provisional until validated.

    line 40
  7. Distinctive:

    Keep prompts, seeds, model versions, and filtering criteria reproducible.

    line 41
  8. Distinctive:

    Create a schema and examples before generating.

    line 59
  9. Distinctive:

    Remove duplicates, invalid rows, prompt residue, unsafe content, and unrealistic examples.

    line 61
  10. Distinctive:

    Start from the dataset purpose and schema.

    line 74

“Common” is measured: kept by at least 6 in 10 of the 4 edited versions of this file we could read. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.

Keep what fits and drop the rest. Your version, ready for your agents.
Files
SKILL.md

Generate Synthetic Data

Purpose

Help agents generate synthetic data for evals, training, or retrieval tests without drifting away from real failure modes. This skill is for schema-bound, reviewed synthetic examples, not for inventing convenient data at random.

Quick Start

  1. Start from real traces, observed failures, seed examples, or source documents.
  2. Define the schema and allowed labels before generation.
  3. Generate in small batches.
  4. Filter for validity, diversity, realism, privacy, and leakage.
  5. Keep provenance and prompt/config records.
  6. Reserve human review for high-impact or public-facing datasets.

Operating Constraints

  • Do not use synthetic data as a substitute for real traces when real traces exist.
  • Do not generate unsupported facts or private personal details.
  • Do not mix synthetic training rows into eval sets without clear split separation.
  • Treat LLM-generated labels as provisional until validated.
  • Keep prompts, seeds, model versions, and filtering criteria reproducible.

Inputs This Skill Expects

  • Dataset goal: eval, retrieval, SFT, preference data, adversarial cases, or red-team cases.
  • Source traces, documents, seed examples, or failure categories.
  • Output schema and validation rules.
  • Diversity requirements and disallowed content.
  • Review and split strategy.

Output Contract

  • Produce synthetic rows that validate against schema.
  • Include generation provenance and filtering results.
  • State which examples require human review.
  • Separate train, dev, test, and holdout data where relevant.
  • Summarize coverage and known blind spots.

Procedure

  1. Define the target failure modes or coverage categories.
  2. Create a schema and examples before generating.
  3. Generate a small batch and validate it.
  4. Remove duplicates, invalid rows, prompt residue, unsafe content, and unrealistic examples.
  5. Expand in batches only after quality is acceptable.
  6. Assign splits without leakage.
  7. Record prompts, model, seed data, and filters.

Pitfalls And Gotchas

  • Generating broad generic examples that do not match real usage.
  • Letting the model invent facts that appear authoritative.
  • Forgetting near-duplicate leakage between train and eval.
  • Using synthetic labels without calibration.
  • Treating quantity as quality.

Progressive Disclosure

Start from the dataset purpose and schema. Expand into adversarial generation, role contrasts, multi-hop retrieval examples, or training augmentation only after the initial batch validates cleanly.

Verification Pattern

  • Confirm every row passes schema validation.
  • Confirm generated facts are grounded where grounding is required.
  • Confirm duplicates and near-duplicates are removed or labeled intentionally.
  • Confirm splits prevent leakage.
  • Confirm human review covers high-risk rows.

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