sharpening-prompts

sharpening-prompts is a skill for Claude Code, Codex from axiomantic/spellbook. It costs 90 tokens per session (1,824 once invoked), scanned A, original, MIT.

A review process for instructions written for AI systems, including prompts, skills, and subagent guidance.

In plain words
What is it for?
It helps audit or rewrite prompts so their requirements, expected results, and success checks are clearer.
Why use it?
It finds ambiguous wording that could make an AI invent missing details or interpret the instructions inconsistently.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions subagents.

Good fit It helps audit or rewrite prompts so their requirements, expected results, and success checks are clearer.

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Install with agentmods
npx agentmods add skills/axiomantic/spellbook/sharpening-prompts
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 axiomantic/spellbook --skill sharpening-prompts
Clone the repo
git clone --depth 1 https://github.com/axiomantic/spellbook

Made for: Claude Code, Codex.

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 sharpening-prompts

README.md
[![agentmods](https://agentmods.dev/badge/skills/axiomantic/spellbook/sharpening-prompts/github.svg)](https://agentmods.dev/skills/axiomantic/spellbook/sharpening-prompts)
Your own site
<a href="https://agentmods.dev/skills/axiomantic/spellbook/sharpening-prompts"><img src="https://agentmods.dev/badge/skills/axiomantic/spellbook/sharpening-prompts/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 sharpening-prompts

Your own site · 80×15
<a href="https://agentmods.dev/skills/axiomantic/spellbook/sharpening-prompts"><img src="https://agentmods.dev/badge/skills/axiomantic/spellbook/sharpening-prompts.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 90 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,824 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 warn 7 Sept 2026
SkillSpector: 1 finding, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium Excessive Agency · line 70
    Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.
    Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
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 $0.00090 $0.01824
Opus 5.5 $0.00036 $0.00730
Sonnet 5.5 $0.00018 $0.00365
Haiku 4.5 $0.00009 $0.00182

Measured 1mo ago against content hash e75d293702c9, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

sharpening-prompts 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 1mo 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/sharpening-prompts/SKILL.md · 189 lines

How it starts

The opening of the file, as written. The whole thing — 189 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Sharpening Prompts

This is very important to my career. You'd better be sure.

Core Question

"Where would an LLM executor have to guess?"

Ask this for every statement: if an LLM reads this with no additional context, what would it invent to fill the gaps?

Reasoning Schema

Invariant Principles

  1. Ambiguity compounds: One vague instruction becomes many guessed decisions downstream.
  2. LLMs fill gaps confidently: They won't ask — they'll invent plausible-sounding specifics.
  3. Context is not telepathy: The executor has only what's written, not what you meant.
  4. Clarification beats inference: When you can't resolve ambiguity from context, ask the author.
  5. Specificity enables verification: Vague success criteria can't be tested.

Inputs / Outputs

Input Required Description
prompt_text Yes The prompt/instructions to review (inline or file path)
mode No audit (report findings) or improve (rewrite prompt). Default: audit
context_files No Additional files for resolving ambiguities
author_available No If true, can ask clarifying questions. Default: false
Output Type Description
findings_report Inline Categorized findings with severity and remediation
improved_prompt Inline/File Rewritten prompt (improve mode only)
clarification_requests Inline Questions for author if ambiguities unresolvable

Read the full file on GitHub · 189 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. 1mo ago First seen · 189 lines · 90 tokens per session scan A e75d293702c9

Subscribe to this mod's changes

sharpening-prompts is a skill published in the GitHub repository axiomantic/spellbook (10 stars, last pushed 2d ago), licensed MIT. It adds 90 tokens to every session and 1,824 once invoked, about $0.0004 per session on Opus 5.5. 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 2026-09-03.