Add agent brief and out-of-scope documentation for GitHub issue triage

github-triage/AGENT-BRIEF.md

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+# Writing Agent Briefs
+
+An agent brief is a structured comment posted on a GitHub issue when it moves to `ready-for-agent`. It is the authoritative specification that an AFK agent will work from. The original issue body and discussion are context — the agent brief is the contract.
+
+## Principles
+
+### Durability over precision
+
+The issue may sit in `ready-for-agent` for days or weeks. The codebase will change in the meantime. Write the brief so it stays useful even as files are renamed, moved, or refactored.
+
+- **Do** describe interfaces, types, and behavioral contracts
+- **Do** name specific types, function signatures, or config shapes that the agent should look for or modify
+- **Don't** reference file paths — they go stale
+- **Don't** reference line numbers
+- **Don't** assume the current implementation structure will remain the same
+
+### Behavioral, not procedural
+
+Describe **what** the system should do, not **how** to implement it. The agent will explore the codebase fresh and make its own implementation decisions.
+
+- **Good:** "The `SkillConfig` type should accept an optional `schedule` field of type `CronExpression`"
+- **Bad:** "Open src/types/skill.ts and add a schedule field on line 42"
+- **Good:** "When a user runs `/triage` with no arguments, they should see a summary of issues needing attention"
+- **Bad:** "Add a switch statement in the main handler function"
+
+### Complete acceptance criteria
+
+The agent needs to know when it's done. Every agent brief must have concrete, testable acceptance criteria. Each criterion should be independently verifiable.
+
+- **Good:** "Running `gh issue list --label needs-triage` returns issues that have been through initial classification"
+- **Bad:** "Triage should work correctly"
+
+### Explicit scope boundaries
+
+State what is out of scope. This prevents the agent from gold-plating or making assumptions about adjacent features.
+
+## Template
+
+```markdown
+## Agent Brief
+
+**Category:** bug / enhancement
+**Summary:** one-line description of what needs to happen
+
+**Current behavior:**
+Describe what happens now. For bugs, this is the broken behavior.
+For enhancements, this is the status quo the feature builds on.
+
+**Desired behavior:**
+Describe what should happen after the agent's work is complete.
+Be specific about edge cases and error conditions.
+
+**Key interfaces:**
+- `TypeName` — what needs to change and why
+- `functionName()` return type — what it currently returns vs what it should return
+- Config shape — any new configuration options needed
+
+**Acceptance criteria:**
+- [ ] Specific, testable criterion 1
+- [ ] Specific, testable criterion 2
+- [ ] Specific, testable criterion 3
+
+**Out of scope:**
+- Thing that should NOT be changed or addressed in this issue
+- Adjacent feature that might seem related but is separate
+```
+
+## Examples
+
+### Good agent brief (bug)
+
+```markdown
+## Agent Brief
+
+**Category:** bug
+**Summary:** Skill description truncation drops mid-word, producing broken output
+
+**Current behavior:**
+When a skill description exceeds 1024 characters, it is truncated at exactly
+1024 characters regardless of word boundaries. This produces descriptions
+that end mid-word (e.g. "Use when the user wants to confi").
+
+**Desired behavior:**
+Truncation should break at the last word boundary before 1024 characters
+and append "..." to indicate truncation.
+
+**Key interfaces:**
+- The `SkillMetadata` type's `description` field — no type change needed,
+  but the validation/processing logic that populates it needs to respect
+  word boundaries
+- Any function that reads SKILL.md frontmatter and extracts the description
+
+**Acceptance criteria:**
+- [ ] Descriptions under 1024 chars are unchanged
+- [ ] Descriptions over 1024 chars are truncated at the last word boundary
+      before 1024 chars
+- [ ] Truncated descriptions end with "..."
+- [ ] The total length including "..." does not exceed 1024 chars
+
+**Out of scope:**
+- Changing the 1024 char limit itself
+- Multi-line description support
+```
+
+### Good agent brief (enhancement)
+
+```markdown
+## Agent Brief
+
+**Category:** enhancement
+**Summary:** Add `.out-of-scope/` directory support for tracking rejected feature requests
+
+**Current behavior:**
+When a feature request is rejected, the issue is closed with a `wontfix` label
+and a comment. There is no persistent record of the decision or reasoning.
+Future similar requests require the maintainer to recall or search for the
+prior discussion.
+
+**Desired behavior:**
+Rejected feature requests should be documented in `.out-of-scope/<concept>.md`
+files that capture the decision, reasoning, and links to all issues that
+requested the feature. When triaging new issues, these files should be
+checked for matches.
+
+**Key interfaces:**
+- Markdown file format in `.out-of-scope/` — each file should have a
+  `# Concept Name` heading, a `**Decision:**` line, a `**Reason:**` line,
+  and a `**Prior requests:**` list with issue links
+- The triage workflow should read all `.out-of-scope/*.md` files early
+  and match incoming issues against them by concept similarity
+
+**Acceptance criteria:**
+- [ ] Closing a feature as wontfix creates/updates a file in `.out-of-scope/`
+- [ ] The file includes the decision, reasoning, and link to the closed issue
+- [ ] If a matching `.out-of-scope/` file already exists, the new issue is
+      appended to its "Prior requests" list rather than creating a duplicate
+- [ ] During triage, existing `.out-of-scope/` files are checked and surfaced
+      when a new issue matches a prior rejection
+
+**Out of scope:**
+- Automated matching (human confirms the match)
+- Reopening previously rejected features
+- Bug reports (only enhancement rejections go to `.out-of-scope/`)
+```
+
+### Bad agent brief
+
+```markdown
+## Agent Brief
+
+**Summary:** Fix the triage bug
+
+**What to do:**
+The triage thing is broken. Look at the main file and fix it.
+The function around line 150 has the issue.
+
+**Files to change:**
+- src/triage/handler.ts (line 150)
+- src/types.ts (line 42)
+```
+
+This is bad because:
+- No category
+- Vague description ("the triage thing is broken")
+- References file paths and line numbers that will go stale
+- No acceptance criteria
+- No scope boundaries
+- No description of current vs desired behavior

github-triage/OUT-OF-SCOPE.md

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+# Out-of-Scope Knowledge Base
+
+The `.out-of-scope/` directory in a repo stores persistent records of rejected feature requests. It serves two purposes:
+
+1. **Institutional memory** — why a feature was rejected, so the reasoning isn't lost when the issue is closed
+2. **Deduplication** — when a new issue comes in that matches a prior rejection, the skill can surface the previous decision instead of re-litigating it
+
+## Directory structure
+
+```
+.out-of-scope/
+├── dark-mode.md
+├── plugin-system.md
+└── graphql-api.md
+```
+
+One file per **concept**, not per issue. Multiple issues requesting the same thing are grouped under one file.
+
+## File format
+
+The file should be written in a relaxed, readable style — more like a short design document than a database entry. Use paragraphs, code samples, and examples to make the reasoning clear and useful to someone encountering it for the first time.
+
+```markdown
+# Dark Mode
+
+This project does not support dark mode or user-facing theming.
+
+## Why this is out of scope
+
+The rendering pipeline assumes a single color palette defined in
+`ThemeConfig`. Supporting multiple themes would require:
+
+- A theme context provider wrapping the entire component tree
+- Per-component theme-aware style resolution
+- A persistence layer for user theme preferences
+
+This is a significant architectural change that doesn't align with the
+project's focus on content authoring. Theming is a concern for downstream
+consumers who embed or redistribute the output.
+
+```ts
+// The current ThemeConfig interface is not designed for runtime switching:
+interface ThemeConfig {
+  colors: ColorPalette; // single palette, resolved at build time
+  fonts: FontStack;
+}
+```
+
+## Prior requests
+
+- #42 — "Add dark mode support"
+- #87 — "Night theme for accessibility"
+- #134 — "Dark theme option"
+```
+
+### Naming the file
+
+Use a short, descriptive kebab-case name for the concept: `dark-mode.md`, `plugin-system.md`, `graphql-api.md`. The name should be recognizable enough that someone browsing the directory understands what was rejected without opening the file.
+
+### Writing the reason
+
+The reason should be substantive — not "we don't want this" but why. Good reasons reference:
+
+- Project scope or philosophy ("This project focuses on X; theming is a downstream concern")
+- Technical constraints ("Supporting this would require Y, which conflicts with our Z architecture")
+- Strategic decisions ("We chose to use A instead of B because...")
+
+The reason should be durable. Avoid referencing temporary circumstances ("we're too busy right now") — those aren't real rejections, they're deferrals.
+
+## When to check `.out-of-scope/`
+
+During triage (Step 1: Gather context), read all files in `.out-of-scope/`. When evaluating a new issue:
+
+- Check if the request matches an existing out-of-scope concept
+- Matching is by concept similarity, not keyword — "night theme" matches `dark-mode.md`
+- If there's a match, surface it to the maintainer: "This is similar to `.out-of-scope/dark-mode.md` — we rejected this before because [reason]. Do you still feel the same way?"
+
+The maintainer may:
+
+- **Confirm** — the new issue gets added to the existing file's "Prior requests" list, then closed
+- **Reconsider** — the out-of-scope file gets deleted or updated, and the issue proceeds through normal triage
+- **Disagree** — the issues are related but distinct, proceed with normal triage
+
+## When to write to `.out-of-scope/`
+
+Only when an **enhancement** (not a bug) is rejected as `wontfix`. The flow:
+
+1. Maintainer decides a feature request is out of scope
+2. Check if a matching `.out-of-scope/` file already exists
+3. If yes: append the new issue to the "Prior requests" list
+4. If no: create a new file with the concept name, decision, reason, and first prior request
+5. Post a comment on the issue explaining the decision and mentioning the `.out-of-scope/` file
+6. Close the issue with the `wontfix` label
+
+## Updating or removing out-of-scope files
+
+If the maintainer changes their mind about a previously rejected concept:
+
+- Delete the `.out-of-scope/` file
+- The skill does not need to reopen old issues — they're historical records
+- The new issue that triggered the reconsideration proceeds through normal triage

github-triage/SKILL.md

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+---
+name: github-triage
+description: Triage GitHub issues through a label-based state machine with interactive grilling sessions. Use when user wants to triage issues, review incoming bugs or feature requests, prepare issues for an AFK agent, or manage issue workflow.
+---
+
+# GitHub Issue Triage
+
+Triage issues in the current repo using a label-based state machine. Infer the repo from `git remote`. Use `gh` for all GitHub operations.
+
+## Reference docs
+
+- [AGENT-BRIEF.md](AGENT-BRIEF.md) — how to write durable agent briefs
+- [OUT-OF-SCOPE.md](OUT-OF-SCOPE.md) — how the `.out-of-scope/` knowledge base works
+
+## Labels
+
+| Label             | Type     | Description                              |
+| ----------------- | -------- | ---------------------------------------- |
+| `bug`             | Category | Something is broken                      |
+| `enhancement`     | Category | New feature or improvement               |
+| `needs-triage`    | State    | Maintainer needs to evaluate this issue  |
+| `needs-info`      | State    | Waiting on reporter for more information |
+| `ready-for-agent` | State    | Fully specified, ready for AFK agent     |
+| `ready-for-human` | State    | Requires human implementation            |
+| `wontfix`         | State    | Will not be actioned                     |
+
+Every issue should have exactly **one** state label and **one** category label. If an issue has conflicting state labels (e.g. both `needs-triage` and `ready-for-agent`), flag the conflict and ask the maintainer which state is correct before doing anything else. Provide a recommendation.
+
+## State Machine
+
+| Current State  | Can transition to | Who triggers it        | What happens                                                                                                         |
+| -------------- | ----------------- | ---------------------- | -------------------------------------------------------------------------------------------------------------------- |
+| `unlabeled`    | `needs-triage`    | Skill (on first look)  | Issue needs maintainer evaluation. Skill applies label after presenting recommendation.                              |
+| `unlabeled`    | `ready-for-agent` | Maintainer (via skill) | Issue is already well-specified and agent-suitable. Skill writes agent brief comment, applies label.                 |
+| `unlabeled`    | `ready-for-human` | Maintainer (via skill) | Issue requires human implementation. Skill writes a brief comment summarizing the task, applies label.               |
+| `unlabeled`    | `wontfix`         | Maintainer (via skill) | Issue is spam, duplicate, or out of scope. Skill closes with comment (and writes `.out-of-scope/` for enhancements). |
+| `needs-triage` | `needs-info`      | Maintainer (via skill) | Issue is underspecified. Skill posts triage notes capturing progress so far + questions for reporter.                |
+| `needs-triage` | `ready-for-agent` | Maintainer (via skill) | Grilling session complete, agent-suitable. Skill writes agent brief comment, applies label.                          |
+| `needs-triage` | `ready-for-human` | Maintainer (via skill) | Grilling session complete, needs human. Skill writes a brief comment summarizing the task, applies label.            |
+| `needs-triage` | `wontfix`         | Maintainer (via skill) | Maintainer decides not to action. Skill closes with comment (and writes `.out-of-scope/` for enhancements).          |
+| `needs-info`   | `needs-triage`    | Skill (detects reply)  | Reporter has replied. Skill surfaces to maintainer for re-evaluation.                                                |
+
+An issue can only move along these transitions. The maintainer can override any state directly (see Quick State Override below), but the skill should flag if the transition is unusual.
+
+## Invocation
+
+The maintainer invokes `/github-triage` then describes what they want in natural language. The skill interprets the request and takes the appropriate action.
+
+Example requests:
+
+- "Show me anything that needs my attention"
+- "Let's look at #42"
+- "Move #42 to ready-for-agent"
+- "What's ready for agents to pick up?"
+- "Are there any unlabeled issues?"
+
+## Workflow: Show What Needs Attention
+
+When the maintainer asks for an overview, query GitHub and present a summary grouped into three buckets:
+
+1. **Unlabeled issues** — new, no labels at all. These have never been triaged.
+2. **`needs-triage` issues** — maintainer needs to evaluate or continue evaluating.
+3. **`needs-info` issues with new activity** — the reporter has commented since the last triage notes comment. Check comment timestamps to determine this.
+
+Display counts per group. Within each group, show issues oldest first (longest-waiting gets attention first). For each issue, show: number, title, age, and a one-line summary of the issue body.
+
+Let the maintainer pick which issue to dive into.
+
+## Workflow: Triage a Specific Issue
+
+### Step 1: Gather context
+
+Before presenting anything to the maintainer:
+
+- Read the full issue: body, all comments, all labels, who reported it, when
+- If there are prior triage notes comments (from previous sessions), parse them to understand what has already been established
+- Explore the codebase to build context — understand the domain, relevant interfaces, and existing behavior related to the issue
+- Read `.out-of-scope/*.md` files and check if this issue matches or is similar to a previously rejected concept
+
+### Step 2: Present a recommendation
+
+Tell the maintainer:
+
+- **Category recommendation:** bug or enhancement, with reasoning
+- **State recommendation:** where this issue should go, with reasoning
+- If it matches a prior out-of-scope rejection, surface that: "This is similar to `.out-of-scope/concept-name.md` — we rejected this before because X. Do you still feel the same way?"
+- A brief summary of what you found in the codebase that's relevant
+
+Then wait for the maintainer's direction. They may:
+
+- Agree and ask you to apply labels → do it
+- Want to flesh it out → start a grilling session
+- Override with a different state → apply their choice
+- Want to discuss → have a conversation
+
+### Step 3: Bug reproduction (bugs only)
+
+If the issue is categorized as a bug, attempt to reproduce it before starting a grilling session. This will vary by codebase, but do your best:
+
+- Read the reporter's reproduction steps (if provided)
+- Explore the codebase to understand the relevant code paths
+- Try to reproduce the bug: run tests, execute commands, or trace the logic to confirm the reported behavior
+- If reproduction succeeds, report what you found to the maintainer — include the specific behavior you observed and where in the code it originates
+- If reproduction fails, report that too — the bug may be environment-specific, already fixed, or the report may be inaccurate
+- If the report lacks enough detail to attempt reproduction, note that — this is a strong signal the issue should move to `needs-info`
+
+The reproduction attempt informs the grilling session and the agent brief. A confirmed reproduction with a known code path makes for a much stronger brief.
+
+### Step 4: Grilling session (if needed)
+
+If the issue needs to be fleshed out before it's ready for an agent, interview the maintainer to build a complete specification. Follow the /grill-me pattern:
+
+- Ask questions one at a time
+- Provide a recommended answer for each question
+- If a question can be answered by exploring the codebase, explore the codebase instead
+- If there are prior triage notes on this issue, resume from where you left off — never re-ask questions that were already resolved
+- For bugs: use the reproduction findings to ask targeted questions ("I confirmed this happens because X — should the fix be Y or Z?")
+
+The goal is to reach a point where you can write a complete agent brief. Keep going until you have:
+
+- A clear summary of the desired behavior
+- Concrete acceptance criteria
+- Key interfaces that may need to change
+- A clear boundary of what's out of scope
+
+### Step 5: Apply the outcome
+
+Before posting any comment or applying any label, show the maintainer a **preview** of exactly what will be posted and which labels will be applied/removed. Only proceed on confirmation.
+
+Depending on the outcome:
+
+- **ready-for-agent** — post an agent brief comment (see [AGENT-BRIEF.md](AGENT-BRIEF.md))
+- **ready-for-human** — post a comment summarizing the task, what was established during triage, and why it needs human implementation. Use the same structure as an agent brief but note the reason it can't be delegated to an agent (e.g. requires judgment calls, external system access, design decisions, or manual testing).
+- **needs-info** — post triage notes with progress so far and questions for the reporter (see Needs Info Output below)
+- **wontfix (bug)** — post a polite comment explaining why, then close the issue
+- **wontfix (enhancement)** — write to `.out-of-scope/`, post a comment linking to it, then close the issue (see [OUT-OF-SCOPE.md](OUT-OF-SCOPE.md))
+- **needs-triage** — apply the label. Optionally leave a comment if there's partial progress to capture.
+
+## Workflow: Quick State Override
+
+When the maintainer explicitly tells you to move an issue to a specific state (e.g. "move #42 to ready-for-agent"), trust their judgment and apply the label directly.
+
+Still show a confirmation of what you're about to do: which labels will be added/removed, and whether you'll post a comment or close the issue. But skip the grilling session entirely.
+
+If moving to `ready-for-agent` without a grilling session, ask the maintainer if they want to write a brief agent brief comment or skip it.
+
+## Needs Info Output
+
+When moving an issue to `needs-info`, post a comment that captures the grilling progress and tells the reporter what's needed:
+
+```markdown
+## Triage Notes
+
+**What we've established so far:**
+
+- point 1
+- point 2
+
+**What we still need from you (@reporter):**
+
+- question 1
+- question 2
+```
+
+Include everything resolved during the grilling session in "established so far" — this work should not be lost. The questions for the reporter should be specific and actionable, not vague ("please provide more info").
+
+## Resuming Previous Sessions
+
+When triaging an issue that already has triage notes from a previous session:
+
+1. Read all comments to find prior triage notes
+2. Parse what was already established
+3. Check if the reporter has answered any outstanding questions
+4. Present the maintainer with an updated picture: "Here's where we left off, and here's what the reporter has said since"
+5. Continue the grilling from where it stopped — do not re-ask resolved questions