fable-voice

fable-voice is a skill for Claude Code from rennf93/opus-fable-playbook. It costs 42 tokens per session (531 once invoked), scanned A, original, MIT.

A writing guide for Fable that sets rules for user-facing conclusions, summaries, pull-request descriptions, and commit messages. It requires the result to come first and the explanation to remain complete and easy to read.

In plain words
What is it for?
Use it when writing final replies, project summaries, pull-request descriptions, commit messages, or other conclusions presented to users or teammates.
Why use it?
It prevents final messages from hiding the important outcome inside process details or vague claims. Readers can quickly understand what happened, what was checked, and what remains uncertain.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the fable-mode plugin — 3 skills, 2 commands, 1 agent, 7 hooks shipped together

Good fit Use it when writing final replies, project summaries, pull-request descriptions, commit messages, or other conclusions presented to users or teammates.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/rennf93/opus-fable-playbook/fable-voice
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add rennf93/opus-fable-playbook --skill fable-voice
Clone the repo
git clone --depth 1 https://github.com/rennf93/opus-fable-playbook

Made for: Claude Code.

Or install fable-mode, the plugin that ships this one along with the rest of its 3 skills, 2 commands, 1 agent, 7 hooks.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for fable-voice

README.md
[![agentmods](https://agentmods.dev/badge/skills/rennf93/opus-fable-playbook/fable-voice/github.svg)](https://agentmods.dev/skills/rennf93/opus-fable-playbook/fable-voice)
Your own site
<a href="https://agentmods.dev/skills/rennf93/opus-fable-playbook/fable-voice"><img src="https://agentmods.dev/badge/skills/rennf93/opus-fable-playbook/fable-voice/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for fable-voice

Your own site · 80×15
<a href="https://agentmods.dev/skills/rennf93/opus-fable-playbook/fable-voice"><img src="https://agentmods.dev/badge/skills/rennf93/opus-fable-playbook/fable-voice.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 42 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 531 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00042 $0.00531
Opus 5 $0.00021 $0.00266
Sonnet 5 $0.00008 $0.00106
Haiku 4.5 $0.00004 $0.00053

Measured 11d ago against content hash a6b339ed6806, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

fable-voice scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 11d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/fable-voice/SKILL.md · 45 lines

What it actually says

Fable Voice

The final message is the product. Run this checklist over your draft:

  1. First sentence = the outcome. "What happened / what did I find" — the thing the user would ask for as the TLDR. Not your process.
  2. Complete. Everything the user needs is IN this message — findings from mid-turn, caveats from your thinking. They read nothing else. A bare "done" or "verified" is not content by itself — pair it with the facts that prove it (what changed, where, how you checked).
  3. Prose first. Simple question → direct prose answer, zero headers. Headers/bullets only when structure genuinely aids scanning. Tables only for short enumerable facts.
  4. Sentences, not fragments. No arrow chains (A → B → fails), no invented shorthand, no unexplained codenames. Spell terms out.
  5. Selective, not compressed. Cut what doesn't change the reader's next action; write what remains in full sentences.
  6. No hedging on verified facts; no claims on unverified ones.

Bad → good

Buried lede: "I started by reading the config loader, then traced the env override path, then checked the CI logs, and found the deploy fails because DATABASE_URL is unset in staging." → "The deploy fails because DATABASE_URL is unset in staging. I traced it through the config loader's env override path and confirmed in the CI logs."

Header spam (for "is X safe to delete?"): "## Analysis\n### Usage\n- 0 references\n### Risk\n- low\n## Conclusion\n- safe" → "Yes — legacy_export() has no references anywhere in the repo, so it's safe to delete. The only mention is its own definition at export.py:112."

Arrow chain: "auth → middleware → session lookup → returns stale token → 401" → "The 401 happens because the middleware's session lookup returns a stale token after rotation."

Hedge after verification: "This should hopefully fix the issue." → "Fixed and verified: the full suite passes (42 passed in 3.1s)."

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 11d ago First seen · 45 lines · 42 tokens per session scan A a6b339ed6806

Subscribe to this mod's changes

fable-voice is a skill published in the GitHub repository rennf93/opus-fable-playbook (34 stars, last pushed 2mo ago), licensed MIT. It adds 42 tokens to every session and 531 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

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