| name | missingness-mechanism-investigator |
| description | Diagnose missing-data mechanisms and design imputation, exclusion, or sensitivity plans. Use when an agent needs a judgment-heavy data science workflow for diagnose missing data before imputation, including evidence review, local artifact inspection, risk classification, stakeholder-ready decisions, reproducibility, governance, or agent-to-agent handoff. Trigger for Codex, Claude, Gemini, Copilot, Cursor, Windsurf, Gravity, LangGraph, CrewAI, AutoGen, or local agents when this exact workflow is needed. |
Missingness Mechanism Investigator
Mission
Diagnose missing-data mechanisms and design imputation, exclusion, or sensitivity plans.
Current pain point: Missing values are filled or dropped mechanically, creating bias and false confidence.
Why this skill exists: MCAR, MAR, and MNAR require different assumptions; the skill forces mechanism thinking before imputation.
Operating Rules
- Start by restating the decision this skill is supporting.
- Inspect local artifacts first before asking for context.
- Treat scripts as evidence collectors, not as substitutes for judgment.
- Preserve raw data, notebooks, configs, and model artifacts unless the user explicitly asks for mutation.
- Mark missing context as
unknown, not provided, or owner decision; do not invent it.
- Classify each blocker as
stop, fix-first, monitor, accepted risk, or owner decision.
- Use the output contract exactly unless the user asks for a different format.
- Keep final recommendations auditable: every important claim needs evidence, assumption, or caveat.
What This Skill Must Do
- Transform a vague request into an explicit Missingness Mechanism Investigator decision with named owner, evidence, assumptions, and action threshold.
- Inspect local artifacts first: data extracts, schemas, notebooks, SQL, pipeline configs, model reports, tickets, and prior decisions.
- Separate mechanical checks from expert judgment so another reviewer can reproduce what was checked and what was inferred.
- Classify findings as stop, fix-first, monitor, accepted risk, or owner decision instead of producing generic advice.
- Preserve raw evidence and never silently mutate data, notebooks, model artifacts, or production configs.
- Return a decision artifact that can be handed to a data scientist, ML engineer, governance reviewer, or stakeholder without hidden context.
Required Inputs
- dataset
- analysis goal
- column meanings
- collection process
- known reasons for missingness
If an input is missing, inspect available files first. Ask only for information that cannot be recovered from the workspace and would change the recommendation.
Workflow
- Profile missingness by column, row, group, time, and target relationship.
- Classify likely mechanisms as MCAR, MAR, MNAR, structural missing, or unknown.
- Identify whether missingness itself should be a feature, exclusion reason, or bias warning.
- Recommend complete-case, imputation, indicator, model-based, or sensitivity strategy.
- Return a missingness report with assumptions and impact on claims.
Red Flags
- target-dependent missingness
- structural missing treated as random
- imputed identifiers
- dropped rows change population
- no collection-process explanation
When a red flag appears, slow down and surface it in Risks. A red flag does not always mean stop, but it must change the recommendation or the confidence level.
Resources
- Read
references/playbook.md for the skill-specific checklist, scoring rubric, and failure modes.
- Read
references/acceptance-tests.md before forward-testing clean, messy, and adversarial requests.
- Read
references/agent-portability.md when adapting this skill to Claude, Gemini, Copilot, Cursor, Windsurf, Gravity, LangGraph, CrewAI, AutoGen, or local agents.
- Read
references/quality-rubric.md when reviewing whether the output meets senior data-science standards.
- Use
scripts/quick_validate_skill.py . --strict before publishing or installing the skill.
Use only the specific reference file needed for the task; keep context small.
Output Contract
Return these sections unless the user requests another format:
Problem: the decision, artifact, model, data source, or workflow being handled.
Inputs: files, data, stakeholder context, assumptions, and missing context used.
Checks performed: concrete inspections, scripts, and reasoning checks.
Findings: prioritized observations with evidence.
Decision: go, fix-first, stop, proceed-with-risk, or needs-owner-review.
Risks: unresolved blockers, caveats, and owner decisions.
Next actions: smallest useful follow-up steps.
Artifacts: generated files, specs, reports, scripts, or links.
Final Checks
- Did the response answer the actual decision, not just analyze data?
- Did it preserve evidence and avoid silent mutation?
- Did it name unknowns and owner decisions?
- Did it include at least one concrete next action?
- Did it avoid overclaiming causality, readiness, compliance, or production safety?