fable-advisor

fable-advisor is a skill for Claude Code from richkuo/rk-skills. It costs 108 tokens per session (1,832 once invoked), scanned A, original, MIT.

A workflow where one Fable 5 subagent advises the current coding session while another independently reviews the work. Fable 5 is the model used for these supporting agents.

In plain words
What is it for?
Use it to execute a task from a GitHub issue or a written description, with an advisor helping plan and a reviewer giving the final pre-commit assessment.
Why use it?
It adds planning checkpoints and a separate review before changes are committed. This helps catch problems during larger coding tasks or GitHub issue work.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: mentions CLAUDE.md; mentions subagents.

Part of the rk-skills plugin — 37 skills, 1 command shipped together

Good fit Use it to execute a task from a GitHub issue or a written description, with an advisor helping plan and a reviewer giving the final pre-commit assessment.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/richkuo/rk-skills/fable-advisor
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 richkuo/rk-skills --skill fable-advisor
Clone the repo
git clone --depth 1 https://github.com/richkuo/rk-skills

Made for: Claude Code.

Or install rk-skills, the plugin that ships this one along with the rest of its 37 skills, 1 command.

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-advisor

README.md
[![agentmods](https://agentmods.dev/badge/skills/richkuo/rk-skills/fable-advisor/github.svg)](https://agentmods.dev/skills/richkuo/rk-skills/fable-advisor)
Your own site
<a href="https://agentmods.dev/skills/richkuo/rk-skills/fable-advisor"><img src="https://agentmods.dev/badge/skills/richkuo/rk-skills/fable-advisor/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-advisor

Your own site · 80×15
<a href="https://agentmods.dev/skills/richkuo/rk-skills/fable-advisor"><img src="https://agentmods.dev/badge/skills/richkuo/rk-skills/fable-advisor.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 108 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,832 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00108 $0.01832
Opus 5 $0.00054 $0.00916
Sonnet 5 $0.00022 $0.00366
Haiku 4.5 $0.00011 $0.00183

Measured 3d ago against content hash 8260c348b098, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

fable-advisor 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 3d 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-advisor/SKILL.md · 93 lines

How it starts

The opening of the file, as written. The whole thing — 93 lines — stays where its author put it; the contents beside it link to each section on GitHub.

fable-advisor

The main agent (the executor) builds. A persistent Fable 5.1 advisor subagent writes the plan and answers checkpoint consults. A separate fresh Fable 5.1 reviewer gives the binding pre-commit verdict, so the plan's author never grades its own build. Never merge the two roles. An issue task runs work-on-issue's pipeline; a prose task takes a lighter path.

Input

An issue reference (URL, #<N>, <N>, owner/repo#N), a prose task, or both (the issue defines the task, the prose adds constraints). With an issue, the plan and the verdict are also posted as issue comments. Ask what to execute only when none is clear. With no issue, never invent one or post anywhere.

Model check

If the main agent already runs on Fable 5.1, say the advisor is redundant and ask whether to proceed, run the task directly, or switch to Sonnet first (/model sonnet).

Steps

1. Resolve and gate-check the issue (only if one is referenced)

gh issue view <N> --json number,title,body,url (add -R owner/repo for another repository). If it fails, stop and tell the user; never plan from a paraphrase. Record the number, title, and URL. Then run the two gates of work-on-issue step 0, before any advisor is spawned. With no issue, skip steps 3 and 8.

2. Spawn the advisor and get the plan

The advisor owns the plan; do not plan yourself. Load fable-dispatch before dispatching; its section 7 hygiene rules also govern the step 6 reviewer. Agent-tool path: subagent_type: Plan, model: fable, run_in_background: false, description: Advise on <short task name>. The prompt briefs a standing, read-only advisor with the full task (issue title and body for a bare reference), the working directory, the user's constraints, and its charter:

  • First deliverable: a concrete, ordered plan with the implementation steps numbered, each ending in a verify point (the check that proves it done). Plan the absolute-best solution per CLAUDE.md.
  • Each consult reply carries recommendation, rationale, confidence (high/medium/low), and a flag: advisory (the executor may overrule with a stated reason) or blocking (must be resolved before commit).

Read the full file on GitHub · 93 lines

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. 3d ago Changed · -31 lines 8260c348b098
  2. 5d ago Changed · -53 lines · -67 tokens per session 6bb1b6c701e9
  3. 10d ago First seen · 177 lines · 175 tokens per session scan A 540c663b76be

Subscribe to this mod's changes

fable-advisor is a skill published in the GitHub repository richkuo/rk-skills (49 stars, last pushed today), licensed MIT. It adds 108 tokens to every session and 1,832 once invoked, about $0.0005 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.