# Parallel Investigate > 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 i - Skill: `hideki5123/parallel-investigate` (Agent Skill, multi-file: 5 files) - Install (CLI): `npx skillmds@latest add hideki5123/parallel-investigate` - Raw SKILL.md: https://api.skillmd.com/api/skills/hideki5123/parallel-investigate/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: AI & ML - Author: hideki5123 (https://skillmd.com/u/hideki5123) - Updated: 2026-09-22 - Page: https://skillmd.com/skills/hideki5123/parallel-investigate --- # 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:`, `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 `` if it does not exist). c. Prepend a new entry directly after the header: ```markdown ## - **Skill Version**: 1.0.0 - **Task**: - **Outcome**: success | partial-success | failure | error - **Rating**: /5 (or "—" if not provided) - **Rating reason**: - **Corrections**: - **Issues**: - **User Note**: --- ``` d. Confirm in one short Japanese sentence. 4. If the user skips AND no corrections or issues occurred, end without recording. ## 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.