Individual skill

why

Use for 'why does X work this way', 'why we picked Y', design rationale, regressions, postmortems, or data-backed thresholds. Discovers available MCPs and queries each evidence category (source control, issue tracker, long-form docs, real-time chat, infrastructure observability, error tracking, product analytics warehouse) in parallel, then returns a cited read on decisions and tradeoffs. Use how for runtime behavior.

vendor/pstack/skills/why/SKILL.md

Read pinned source

Source commit 91251ca92b107de606d3958e86454441910f1179

What was checked

Matches the observed repository HEAD: Yes
Scanner rules are current: Yes
Repository scan complete: No
Skill scan complete: No
Observed behavior: Instructions only
Last checked: Nov 5, 2026

These are observations at the recorded commit, not a guarantee of safety. Review the source before running it.

Install this skill

Choose an agent in your Stack or copy a command below. Commands fetch the pinned commit and copy only this skill directory. Existing destinations are refused. Copying a command does not install anything.

An install command is unavailable: current rules, complete repository and skill scans, an eligible behavior level and a permitted license are required.

Repository context

Repository stars (not skill ratings): 18
Repository last updated: Nov 4, 2026
License: MIT

Observed agent integration: No specific integration evidence. Standard SKILL.md installation does not imply verified compatibility.

agent-skills Repository topic
ai-agents Repository topic
claude-code Repository topic
code-review Repository topic
codex Repository topic
developer-tools Repository topic
multi-agent Repository topic
pstack Repository topic
skills Repository topic
t3-code Repository topic
data Derived category
design Derived category
devops Derived category
docs Derived category

Files and excerpt

File metadata and permitted, redacted excerpts come from the recorded scan. Source links are pinned to that commit.

Browse files

SKILL.mdcore · 8,903 bytes
SKILL.mdcore · 8,903 bytes
SKILL.mdcore · 8,903 bytes
SKILL.mdcore · 8,903 bytes
references/epistemics.mddoc · 6,736 bytes
references/investigator-prompt.mddoc · 5,554 bytes
references/source-playbook.mddoc · 1,363 bytes
references/sources/code-archaeology.mddoc · 1,440 bytes
references/sources/databricks.mddoc · 6,994 bytes
references/sources/datadog.mddoc · 4,971 bytes
references/sources/incident-postmortem.mddoc · 372 bytes
references/sources/linear.mddoc · 2,996 bytes
references/sources/notion.mddoc · 2,853 bytes
references/sources/sentry.mddoc · 2,089 bytes
references/sources/slack.mddoc · 1,336 bytes
references/synthesizer-prompt.mddoc · 7,146 bytes

Read excerpt


# Why

Investigate the motivation and intent behind code. The companion `how` skill answers what the code does and how it works. `why` answers what forces led to its shape.

Each spawn below names a role line in the `pstack-models.mdc` rule and a default. Set `model` to that line's value, or to the default if the rule or the line is missing. Leave `model` unset when the value is `auto` or `inherit-parent`. If the Task tool rejects a slug, use the default and say so. If it rejects the default, use the closest valid slug of the same family from its error message. Pick each subagent's reasoning level and fast or standard speed for the job, per the Subagents section of the **poteto-mode** skill.

Every spawn is `generalPurpose` with `readonly: false` (agent mode). **Do not use readonly/Ask mode.** It strips MCP access, which disables the MCP-backed investigators and the synthesizer's citation spot-checks. Investigators still shouldn't write anything.

## Operating Posture

Operate as a **careful, cautious, and precise investigator**. Be honest about what you know vs what you're inferring. Read `references/epistemics.md` for the full confidence framework and phrasing guide. The synthesizer must follow it.

## Step 1. Understand the Target and the Question