Skip to content
Agentmart
Submit a tool

grim:dev:agentops:model-quirks

Model Quirks: Apply model-specific prompt mitigations inline and record every change in the reverse-index ledger so it can be verified, pruned, or undone when…

Skill by MindGoblinStudios

IndexedMIT★ 34
Write a review

Install

Works with Claude Code, Claude apps, Codex, Cursor, Gemini CLI, GitHub Copilot, VS Code, OpenCode, Goose, Windsurf. Read the repository before you give any tool access to your data.

npx agentmarket install skill/mindgoblinstudios-grim-dev-agentops-model-quirks

Asks which of your tools to add it to (Claude Code, Codex, Cursor, VS Code, Windsurf, Gemini CLI, Claude Desktop) and shows the change first. See https://agentmart.dev/cli.

Get the weekly diff

The weekly diff: one email a week with new agent tools, notable updates and grade changes, plus security alerts for tools you follow. Double opt-in, one-click unsubscribe.

We use your email only for this newsletter. Privacy

About

Model Quirks: Apply model-specific prompt mitigations inline and record every change in the reverse-index ledger so it can be verified, pruned, or undone when models rotate.

Use cases: agent-building

No reviews yet. Installed it? Reviews come from verified installers only. How reviews work

Permissions

What this skill can do and what it asks for, from its SKILL.md. Checked Oct 25, 2026.

Tools
No tools found
Secrets
None asked for
Install scripts
None found

Network hosts it talks to 1

  • codeload.github.com · found in install command

Files it touches

  • ~/.claude/skills/grim-dev-agentops-model-quirks

What's inside

Skill name
grim:dev:agentops:model-quirks
Description
Model Quirks: Apply model-specific prompt mitigations inline and record every change in the reverse-index ledger so it can be verified, pruned, or undone when models rotate.
License
MIT
Instructions
66 lines in SKILL.md · view on GitHub

Agent Skills spec issues

  • name: only lowercase letters, digits and single hyphens allowed

Files (6)

  • SKILL.md
  • openai.yaml · agents/
  • newmodelquirks-icon-large.png · assets/
  • newmodelquirks-icon-med.png · assets/
  • newmodelquirks-icon-small.png · assets/
  • icon-generation-2026-05-18.md · assets/prompts/

SKILL.md (first lines)

# Model Quirks

Use this skill when a task is about model-specific instructions, prompt quirks, undoing or pruning old model mitigations, or keeping prompts aligned with the currently used model roster.

## Canonical Files

- Ledger (reverse index + archive): `docs/model-quirks-ledger.yaml`

## The System

Every new model does something weird. Mitigations for those quirks are real prompt text — but they should not outlive the model that needed them.

- **Applied text lives inline.** Mitigations are written directly into `AGENTS.md`, skill files, or whatever prompt they belong in, phrased as normal house rules. No model names, no marker comments, no labeled section. The prompt surface reads as one coherent voice.
- **The ledger is the reverse index.** `docs/model-quirks-ledger.yaml` records, per model, the exact text of every applied change and its target file. The exact recorded text is the undo key — never rely on line numbers, which rot.
- **Applying and recording are one atomic change.** Never add quirk text to a prompt without its ledger entry, and never add a ledger entry without applying the text. Same commit, always.

## Ledger Format

One entry per applied change, under a top-level `entries:` list. Single model id per entry, no aliases. Active and retired entries live in the same file.

```yaml
entries:
  - id: mq-2026-08-22-01
    model: gpt-5.4
    status: active            # active | retired
    applied: 2026-08-22
    target: AGENTS.md
    kind: insert              # insert | edit
    anchor: "## Conventions"  # nearest heading, for locating it
    text: |                   # the exact text as it appears in the file
      Keep progress updates compact and factual.
    before: null              # for kind: edit, the original text
    reason: "5.4 narrates every tool call"
```

Entry rules:
- `text` holds the exact applied text, verbatim — this is the undo key.
- For `kind: edit`, `before` holds the original text; undo restores it.
- `anchor` is a courtesy hint (nearest heading), never the undo key.
- Retired entries keep all fields, flip `status: retired`, and add `retired: YYYY-MM-DD`.
- Keep `reason` short; it's the symptom you were mitigating.

## Workflow

### Applying a mitigation
1. Confirm the quirk is a real recurring default worth overriding, not a one-off.
2. Write the mitigation inline in the smallest right prompt surface, phrased as a normal unlabeled rule in the file's own voice.
3. Add the ledger entry (id, model, target, kind, anchor, exact text, reason) in the same change.

### Retiring a model
1. For each of the model's active entries, find the entry's `text` in its target file and remove it (or restore `before` for edits).
2. If another active model needs the same rule, reassign the entry's `model` instead of deleting the text.
3. Flip each entry to `status: retired` and add `retired: YYYY-MM-DD`. Retired entries are the archive — future models often revive old quirks, so shop them by `reason` before writing new mitigations.

### Verifying (drift check)
Periodically, or before retiring: confirm each active entry's `text` still exists verbatim in its target file. If a mitigation was edited in place, update the entry to match or convert it to `kind: edit` with the right `before`.

## Required Behavior

- No model names or quirk labels in the applied prompt text — the ledger is the only place model attribution lives.
- Never apply without recording; never record without applying.
- Exact quoted text is the undo key. Update the ledger whenever applied text is reworded.
- Keep mitigations short, specific, and focused on real default behaviors worth overriding.
- Prefer concrete model quirks over generic writing advice.
- Update this skill and the ledger header if the workflow or file locations change.

From MindGoblinStudios/grim-tome, MIT.

More from MindGoblinStudios/grim-tome

Signals

Stars
34
Forks
4
Open issues
0
Last commit (this folder)
Oct 12, 2026 (16 days ago)
Last release
Aug 25, 2026 (2 months ago)

From GitHub (fetched Oct 24, 2026).

Details

License
MIT
First seen
Oct 24, 2026
Last checked
Oct 24, 2026

More from MindGoblinStudios

Cite this page

grim:dev:agentops:model-quirks skill. Agent Mart. https://agentmart.dev/skills/mindgoblinstudios-grim-dev-agentops-model-quirks (last updated 2026-10-24)