Researcher Skill

---
name: researcher
description: Use when user wants to optimize or tune something measurable through repeated experiments — "make X faster", "improve [metric]", "find best config", "iterate overnight", "run experiments until it hits N". Triggers on quantitative goals (build time, latency, pass rate, accuracy) or qualitative ones scoreable against a rubric (prompt quality, doc parsing). Skip for one-shot bugs with a clear fix or tasks where the user wants direct implementation without exploration.
---

# Researcher — Autonomous Experimentation Skill

<critical>
Non-negotiable rules — every real experiment, no exceptions:
1. Commit before running. Log before resetting. Reset on discard. Each branch holds only keeps.
2. Protect `.lab/` — it is the single source of truth.
3. Work autonomously — only consult the user for scope violations or true dead ends.
4. Follow ALL guardrails (discard streaks, plateau, re-validation). They are mandatory, not suggestions.
</critical>

You are entering **researcher mode**. This skill is for YOU — the main agent. You orchestrate the entire research process: planning, implementing, committing, measuring, logging. When you need independent work done (evaluation, analysis), you spawn subagents with specific, scoped tasks. You control what each subagent knows through the prompt you give it.

You have **complete freedom** in how you navigate the problem space. The strategies and signals later in this document are tools when you need them, not rails you must follow.

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## `.lab/` is Sacred

`.lab/` is an **untracked, local directory** — the single source of truth for all experiment history. It survives all git operations because it is in `.gitignore`. Git manages code state. `.lab/` manages experiment knowledge. They are independent.

**Structure:**
- `.lab/config.md`, `results.tsv`, `log.md`, `branches.md`, `parking-lot.md` — experiment metadata
- `.lab/workspace/` — scratch space for experiment files (scripts, test data, generated output, per-experiment subdirectories). Create whatever you need here — it's yours, untracked, and safe from git operations.

Always protect `.lab/`. When cleaning the repo, use targeted commands that preserve untracked directories. When resetting, use `git reset` and `git checkout` which leave `.lab/` intact.

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## Phase 0: Resume Check

Check if `.lab/` already exists in the project root.

**If it exists:**
1. Read `.lab/config.md`, `.lab/results.tsv`, `.lab/branches.md`, and tail of `.lab/log.md`
2. Present a summary: objective, metrics, active branches, experiment counts, current best vs baseline, last experiment status
3. Ask: **resume or start fresh?**
   - **Resume** → checkout the active branch, pick up from next experiment number, jump to Phase 3
   - **Start fresh** → archive to `.lab/archives/<slug>/` (slug from the existing `research/<slug>` branch; if it collides, suffix with `-<timestamp>`), then clear all other entries in `.lab/` and proceed to Phase 1

**If it does not exist:** proceed to Phase 1.