Criticism Self Criticism
HughYau/qiushi-skill
批评与自我批评：在工作完成、阶段验收、收到批评或同类错误反复出现时，对成果和过程做诚实、具体、基于事实的审视，输出可执行的改进项，并处理外来批评而不辩解。触发信号包括 review、复盘、审查、"帮我看看有没有问题"、"你确定吗"；任务刚开始或只是单步查询时不触发。
CRITICAL: Use for mutability issues. An agent skill from fjrevoredo/mini-diarium.
MITAuto-check passed
Install M03 Mutability
$ npx skills add fjrevoredo/mini-diarium --skill m03-mutability -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install fjrevoredo/mini-diarium m03-mutability --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/fjrevoredo/mini-diarium.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/m03-mutability .claude/skills/m03-mutability && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "m03-mutability" agent skill from https://github.com/fjrevoredo/mini-diarium/tree/master/.agents/skills/m03-mutability into .claude/skills/m03-mutability/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "m03-mutability", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/fjrevoredo/mini-diarium/tree/master/.agents/skills/m03-mutabilityType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add fjrevoredo/mini-diarium --skill m03-mutability -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install fjrevoredo/mini-diarium m03-mutability --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/fjrevoredo/mini-diarium.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/m03-mutability .agents/skills/m03-mutability && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "m03-mutability" agent skill from https://github.com/fjrevoredo/mini-diarium/tree/master/.agents/skills/m03-mutability into .agents/skills/m03-mutability/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "m03-mutability", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add fjrevoredo/mini-diarium --skill m03-mutability -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install fjrevoredo/mini-diarium m03-mutability --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/fjrevoredo/mini-diarium.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/m03-mutability .cursor/skills/m03-mutability && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "m03-mutability" agent skill from https://github.com/fjrevoredo/mini-diarium/tree/master/.agents/skills/m03-mutability into .cursor/skills/m03-mutability/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "m03-mutability", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/fjrevoredo/mini-diarium.git --path .agents/skills/m03-mutability--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add fjrevoredo/mini-diarium --skill m03-mutability -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install fjrevoredo/mini-diarium m03-mutability --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/fjrevoredo/mini-diarium.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/m03-mutability .gemini/skills/m03-mutability && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "m03-mutability" agent skill from https://github.com/fjrevoredo/mini-diarium/tree/master/.agents/skills/m03-mutability into .gemini/skills/m03-mutability/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "m03-mutability", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install fjrevoredo/mini-diarium m03-mutabilityInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add fjrevoredo/mini-diarium --skill m03-mutability -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/fjrevoredo/mini-diarium.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/m03-mutability .github/skills/m03-mutability && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "m03-mutability" agent skill from https://github.com/fjrevoredo/mini-diarium/tree/master/.agents/skills/m03-mutability into .github/skills/m03-mutability/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "m03-mutability", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add fjrevoredo/mini-diarium --skill m03-mutability -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install fjrevoredo/mini-diarium m03-mutability --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/fjrevoredo/mini-diarium.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/m03-mutability .opencode/skills/m03-mutability && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "m03-mutability" agent skill from https://github.com/fjrevoredo/mini-diarium/tree/master/.agents/skills/m03-mutability into .opencode/skills/m03-mutability/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "m03-mutability", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
m03-mutability- GitHub stars
- 308
- Used in
- 1 other repo
- Token cost
- ~1k tokens
- SKILL.md length
- 330 words
- Files
- 1
- Skills in repo
- 41
- Repo updated
- First seen
- Licence
- MIT
At a glance
CRITICAL: Use for mutability issues. An agent skill from fjrevoredo/mini-diarium.
- Works in 3 steps: Is mutation necessary? → Who controls mutation? → What's the thread context?
- Mutability issues
- SKILL.md covers Core Question, Error → Design Question, Thinking Prompt and Trace Up ↑, plus 7 more sections
- Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md
What it does
M03 Mutability is an agent skill from fjrevoredo/mini-diarium. CRITICAL: Use for mutability issues. Triggers: E0596, E0499, E0502, cannot borrow as mutable, already borrowed as immutable, mut, &mut, interior mutability, Cell, RefCell, Mutex, RwLock, 可变性, 内部可变性, 借用冲突
Its SKILL.md is about 1k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
The repository describes itself as: A local-only journal with serious encryption. Free, open source, and never touches the internet. The licence is MIT.
When your agent uses it
- Mutability issues
Example prompts
- “/m03-mutability”
Workflow steps
3 steps, taken from the first numbered list in SKILL.md.
- Is mutation necessary?
- Who controls mutation?
- What's the thread context?
What it can do on your machine
Read from SKILL.md and the folder at commit 75c1286. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
M03 Mutability loads about 1k tokens when it runs. Until then it costs about 55 tokens; SKILL.md has 330 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from fjrevoredo/mini-diarium at commit 75c1286, republished under its MIT licence (© fjrevoredo). 330 words, ~1,020 tokens.
Download SKILL.mdSave it as
.claude/skills/m03-mutability/SKILL.md (or your agent's skills folder).- name
- m03-mutability
- description
- CRITICAL: Use for mutability issues. Triggers: E0596, E0499, E0502, cannot borrow as mutable, already borrowed as immutable, mut, &mut, interior mutability, Cell, RefCell, Mutex, RwLock, 可变性, 内部可变性, 借用冲突
- user-invocable
- false
Mutability
Layer 1: Language Mechanics
Core Question
Why does this data need to change, and who can change it?
Before adding interior mutability, understand:
- Is mutation essential or accidental complexity?
- Who should control mutation?
- Is the mutation pattern safe?
Error → Design Question
| Error | Don't Just Say | Ask Instead |
|---|---|---|
| E0596 | "Add mut" | Should this really be mutable? |
| E0499 | "Split borrows" | Is the data structure right? |
| E0502 | "Separate scopes" | Why do we need both borrows? |
| RefCell panic | "Use try_borrow" | Is runtime check appropriate? |
Thinking Prompt
Before adding mutability:
Is mutation necessary?
- Maybe transform → return new value
- Maybe builder → construct immutably
Who controls mutation?
- External caller →
&mut T - Internal logic → interior mutability
- Concurrent access → synchronized mutability
- External caller →
What's the thread context?
- Single-thread → Cell/RefCell
- Multi-thread → Mutex/RwLock/Atomic
Trace Up ↑
When mutability conflicts persist:
E0499/E0502 (borrow conflicts)
↑ Ask: Is the data structure designed correctly?
↑ Check: m09-domain (should data be split?)
↑ Check: m07-concurrency (is async involved?)| Persistent Error | Trace To | Question |
|---|---|---|
| Repeated borrow conflicts | m09-domain | Should data be restructured? |
| RefCell in async | m07-concurrency | Is Send/Sync needed? |
| Mutex deadlocks | m07-concurrency | Is the lock design right? |
Trace Down ↓
From design to implementation:
"Need mutable access from &self"
↓ T: Copy → Cell<T>
↓ T: !Copy → RefCell<T>
"Need thread-safe mutation"
↓ Simple counters → AtomicXxx
↓ Complex data → Mutex<T> or RwLock<T>
"Need shared mutable state"
↓ Single-thread: Rc<RefCell<T>>
↓ Multi-thread: Arc<Mutex<T>>Borrow Rules
At any time, you can have EITHER:
├─ Multiple &T (immutable borrows)
└─ OR one &mut T (mutable borrow)
Never both simultaneously.Quick Reference
| Pattern | Thread-Safe | Runtime Cost | Use When |
|---|---|---|---|
&mut T | N/A | Zero | Exclusive mutable access |
Cell<T> | No | Zero | Copy types, no refs needed |
RefCell<T> | No | Runtime check | Non-Copy, need runtime borrow |
Mutex<T> | Yes | Lock contention | Thread-safe mutation |
RwLock<T> | Yes | Lock contention | Many readers, few writers |
Atomic* | Yes | Minimal | Simple types (bool, usize) |
Error Code Reference
| Error | Cause | Quick Fix |
|---|---|---|
| E0596 | Borrowing immutable as mutable | Add mut or redesign |
| E0499 | Multiple mutable borrows | Restructure code flow |
| E0502 | &mut while & exists | Separate borrow scopes |
Interior Mutability Decision
| Scenario | Choose |
|---|---|
| T: Copy, single-thread | Cell<T> |
| T: !Copy, single-thread | RefCell<T> |
| T: Copy, multi-thread | AtomicXxx |
| T: !Copy, multi-thread | Mutex<T> or RwLock<T> |
| Read-heavy, multi-thread | RwLock<T> |
| Simple flags/counters | AtomicBool, AtomicUsize |
Anti-Patterns
| Anti-Pattern | Why Bad | Better |
|---|---|---|
| RefCell everywhere | Runtime panics | Clear ownership design |
| Mutex for single-thread | Unnecessary overhead | RefCell |
| Ignore RefCell panic | Hard to debug | Handle or restructure |
| Lock inside hot loop | Performance killer | Batch operations |
Related Skills
| When | See |
|---|---|
| Smart pointer choice | m02-resource |
| Thread safety | m07-concurrency |
| Data structure design | m09-domain |
| Anti-patterns | m15-anti-pattern |
© fjrevoredo, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
Just SKILL.md in .agents/skills/m03-mutability of fjrevoredo/mini-diarium.
Open the folder on GitHubat commit 75c1286
Used in 1 other repository
We found 1 copy of this SKILL.md (exact, near-identical or edited) in other folders, from 1 other GitHub owner. This page covers the copy in fjrevoredo/mini-diarium, which our catalogue first saw on October 7, 2026.
Compare with similar skills
M03 Mutability next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| M03 Mutability this skillfjrevoredo/mini-diarium | 308 | 1 repos | ~1k | Automated safety check: Pass | MIT | |
| Criticism Self CriticismHughYau/qiushi-skill | 3.8k | — | ~423 | Automated safety check: Pass | MIT | |
| Crossframe Criticalsickn33/agentic-awesome-skills | 47k | 1 repos | ~1.3k | Automated safety check: Pass | MIT | |
| Critical Imagesthedaviddias/Front-End-Checklist | 74k | — | ~392 | Automated safety check: Pass | MIT | |
| CSS Criticalthedaviddias/Front-End-Checklist | 74k | — | ~441 | Automated safety check: Pass | MIT | |
| Critical Request Chainsthedaviddias/Front-End-Checklist | 74k | — | ~418 | Automated safety check: Pass | MIT |
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Questions about M03 Mutability
What does M03 Mutability do?
CRITICAL: Use for mutability issues. An agent skill from fjrevoredo/mini-diarium. M03 Mutability is an agent skill from fjrevoredo/mini-diarium. CRITICAL: Use for mutability issues.
When should I use M03 Mutability?
M03 Mutability fits situations like: mutability issues.
How do I install M03 Mutability in Claude Code?
Run `npx skills add fjrevoredo/mini-diarium --skill m03-mutability -a claude-code`. Or copy the skill folder (.agents/skills/m03-mutability in fjrevoredo/mini-diarium) into .claude/skills/m03-mutability in your project. Claude Code loads it when a task matches its description.
How do I install M03 Mutability in Codex?
Run `npx skills add fjrevoredo/mini-diarium --skill m03-mutability -a codex`. Or copy the skill folder (.agents/skills/m03-mutability in fjrevoredo/mini-diarium) into .agents/skills/m03-mutability in your project. Codex loads it when a task matches its description.
Can I use M03 Mutability in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add fjrevoredo/mini-diarium --skill m03-mutability -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/m03-mutability, .gemini/skills/m03-mutability, .github/skills/m03-mutability and .opencode/skills/m03-mutability in your project.
What does M03 Mutability need to run?
SKILL.md names no scripts, command-line tools or credentials: M03 Mutability is instructions for the agent only.
Does M03 Mutability access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is M03 Mutability safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does M03 Mutability use?
M03 Mutability is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does M03 Mutability use?
About 1k tokens (SKILL.md is roughly 4.1k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to M03 Mutability?
Skills that share tags, products or a category with M03 Mutability: Criticism Self Criticism (HughYau/qiushi-skill, 3.8k stars), Crossframe Critical (sickn33/agentic-awesome-skills, 47k stars), Critical Images (thedaviddias/Front-End-Checklist, 74k stars) and CSS Critical (thedaviddias/Front-End-Checklist, 74k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains M03 Mutability?
fjrevoredo (a GitHub user) maintains it in fjrevoredo/mini-diarium, which has 308 GitHub stars. The repository holds 41 skills in this directory. The repository was last updated on October 4, 2026.
Source: fjrevoredo/mini-diarium on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.