parallel-investigate

name	parallel-investigate
description	Fans out multiple agents in parallel via the Workflow tool to investigate a codebase question — bug root cause tracing, cross-file or cross-repository behavior tracing, "why does X happen for some cases but not others" questions — then synthesizes a ranked, file:line-cited answer in chat. The point of this skill is explicitness: it announces the investigation dimensions and agent count before launching, narrates progress, and reports a structured synthesis, rather than leaving multi-agent orchestration as an implicit background behavior the user can't see into. Supports investigations that span more than one local repository on disk (e.g. a backend service and a client app that talks to it). Investigation only — does not edit code or fix anything; pair with another skill or a follow-up request for that. Use when the user wants to investigate a bug, trace behavior across files or repositories, understand why something happens under some conditions but not others, or explicitly asks for a parallel/multi-agent investigation. Trigger phrases: "parallel-investigate", "/parallel-investigate", "並列で調査して", "並列調査", "複数エージェントで調べて", "複数エージェントで並列調査して", "investigate this in parallel", "fan out and investigate", "investigate across repos", "trace this across repositories".
version	1.0.0

Parallel Investigate

Investigate a codebase question by fanning out multiple Workflow agents across independent dimensions, then synthesizing their findings into one ranked, cited answer. Always run this via the Workflow tool directly — never simulate the fan-out with sequential Agent calls, and never hide the orchestration from the user. Explicitness is the entire value of this skill over ad hoc investigation.

Feedback Check

If feedback/log.md exists next to this SKILL.md and has 5 or more entries, read the last 10. If a pattern is apparent (the same issue in 3+ entries, or average rating below 3), tell the user (in Japanese): 「過去のフィードバックで類似パターン を検出: [簡潔に]。/skill-improve --skill parallel-investigate で改善案を分析でき ます。」Continue with normal execution either way. If feedback/log.md does not exist, skip silently.

Step 1: Scope the Question

1. Guard against overkill first. If the question can be answered by reading one file or a single targeted grep, say so briefly and just answer it directly — do not launch a Workflow for it. This applies even when the skill was triggered by natural language, not just the slash command.
2. Guard against vagueness. If the request has no concrete subject or codebase area ("調べて" with nothing else, no symptom, no file/module named), ask 1-2 clarifying questions before proceeding. Do not guess dimensions from a request with nothing to decompose.
3. Decompose into investigation dimensions. For genuinely multi-faceted questions, read references/decomposition-patterns.md for the by-layer, by-repository, and by-hypothesis decomposition strategies (with a worked example) before picking dimensions. Aim for 3-5 dimensions.
4. Check for cross-repository scope. If the codebase references an external component whose source is not present in the current repo, do not conclude it's simply unavailable — follow the repo-discovery steps in decomposition-patterns.md (check common sibling-repo roots, then ask the user) before ruling it out.

Step 2: Announce the Plan

Before launching anything, tell the user in one short paragraph: how many dimensions/agents, what each will investigate, and that this runs in the background. Never launch silently — the whole point of this skill is that the user can see the investigation happening, not just receive a final answer.

Step 3: Launch the Workflow

Read references/workflow-template.md for the exact script pattern (Explore phase with one parallel agent per dimension, then a Synthesize phase). Read references/synthesis-format.md for the exact instructions to give the Synthesize agent (ranking, CONFIRMED/PLAUSIBLE confidence tags, contradiction resolution, convergence notes, a concrete next step, ~900-word cap).

Rules that apply regardless of the specific question:

• Every Explore-phase agent prompt must be fully self-contained — agents share no context with you or each other. Restate the symptom/question, name the exact files/dirs (and repo path, if not the current one), and specify exactly what to report back with file:line citations.
• Label every agent (explore:<dimension>, synthesis) so progress in /workflows is legible.
• Use parallel() as the barrier between Explore and Synthesize — synthesis genuinely needs every finding at once to cross-reference and rank them. Do not use pipeline() here even though it's the general default for multi-stage Workflow scripts.
• Before reading any repository you didn't already have open (see Step 1's cross-repo case), check git status first. If it's on a non-default branch with uncommitted changes, investigate the working tree read-only; do not switch branches, stash, or pull without asking.

Step 4: Report Back

Relay the Synthesize agent's output to the user in chat, organized and cited. This skill's default output is chat-only — do not write a report file unless the user separately asks for one to be saved.

Behavior Scenarios

BDD spec lives in references/scenarios.feature. Read only when auditing or amending this skill; not needed for normal execution.

Retrospective

After Step 4 completes, reflect on the investigation:

1. Consider: was the initial decomposition wrong and had to be redone? Did a dimension turn out irrelevant or a needed one get missed? Any Workflow errors, or an agent that returned nothing useful?

2. Ask the user (in Japanese): 「今回の調査のフィードバック (1-5の評価、気になった 点、または何もなければEnter)」 If the user provides a rating < 5, ALWAYS follow up with: 「なぜその評価ですか？ (改善のために具体的に教えてください)」 Record the response verbatim as Rating reason.

3. If the user provides feedback OR corrections/issues actually occurred: a. Create feedback/ next to this SKILL.md if it does not exist. b. Read feedback/log.md (create with # Feedback Log header followed by a blank line and the comment <!-- Append new entries at the top. Do not edit previous entries. --> if it does not exist). c. Prepend a new entry directly after the header:

   ## <ISO-8601 timestamp>
   - **Skill Version**: 1.0.0
   - **Task**: <the question investigated, 1 line>
   - **Outcome**: success | partial-success | failure | error
   - **Rating**: <N>/5 (or "—" if not provided)
   - **Rating reason**: <verbatim WHY answer, or "—" if rating was 5 or not provided>
   - **Corrections**: 
    : 
   
   

References

• references/decomposition-patterns.md — WHEN TO READ: during Step 1, when deciding how to split the question into investigation dimensions (by layer, by repository, by hypothesis) and how to locate a referenced-but-missing repo.
• references/workflow-template.md — WHEN TO READ: during Step 3, as the starting script pattern to adapt for the real investigation.
• references/synthesis-format.md — WHEN TO READ: during Step 3, when writing the Synthesize-phase agent's prompt.
• references/scenarios.feature — WHEN TO READ: only when auditing or amending this skill.