writing-skills

writing-skills is a skill for Claude Code, Codex from EzraApple/skills-init. It costs 35 tokens per session (1,972 once invoked), scanned A, original, MIT.

A set of instructions for creating, editing, packaging, consolidating, routing, validating, or publishing agent skills.

In plain words
What is it for?
Use it when maintaining skills under .agents/skills or another tool-specific skill directory, including defining triggers and verifying skill changes.
Why use it?
It helps keep reusable agent instructions discoverable, focused, and checked against concrete tasks.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: reads .claude/ paths; mentions AGENTS.md.

Good fit Use it when maintaining skills under .agents/skills or another tool-specific skill directory, including defining triggers and verifying skill changes.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/ezraapple/skills-init/writing-skills
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 EzraApple/skills-init --skill writing-skills
Clone the repo
git clone --depth 1 https://github.com/EzraApple/skills-init

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 writing-skills

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

Your own site · 80×15
<a href="https://agentmods.dev/skills/ezraapple/skills-init/writing-skills"><img src="https://agentmods.dev/badge/skills/ezraapple/skills-init/writing-skills.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 35 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,972 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 $0.00035 $0.01972
Opus 5 $0.00017 $0.00986
Sonnet 5 $0.00007 $0.00394
Haiku 4.5 $0.00003 $0.00197

Measured 11d ago against content hash 8aecc43b71f6, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

writing-skills 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/writing-skills/SKILL.md · 245 lines

How it starts

The opening of the file, as written. The whole thing — 245 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Writing Skills

A skill is reusable operational guidance that helps a future agent recognize a situation and apply a proven approach. Treat skill writing like product work for agents: define the job, make discovery reliable, keep the path through the docs obvious, and verify that the skill changes behavior.

Start With Intent

Before writing or editing a skill, answer these from the current task and the target project. Ask only for gaps that cannot be inferred.

  • What task should this help agents do?
  • When should it trigger? Include user phrases, symptoms, tools, paths, and near-miss cases.
  • What should the agent produce or decide after reading it?
  • What 2-3 concrete tasks should it handle end to end?
  • Who is the audience: repository developer agents, user-facing runtime agents, or a packaged skill bundle for many projects?
  • What existing skill, always-on guidance, script, lint, or test already covers part of this?

Those concrete tasks become the should-trigger prompts used during validation.

Choose The Right Home

Do placement before writing content.

Home Use for
.agents/skills/<skill>/SKILL.md Project-local source of truth for reusable skills.
Tool-specific links, such as .claude/skills Generated symlinks or copies that point back to .agents/skills.
AGENTS.md or equivalent always-on guidance Broad rules that should apply even when no skill is invoked.
scripts/, lint, or tests Mechanical behavior that can be enforced automatically.
Runtime workspace skill directory User-facing skills that must be visible to a sandbox or runtime agent.

Search before adding a top-level skill:

rg --files .agents/skills | rg '/SKILL\.md$' | sort
rg -n "keyword|tool|old-skill-name" .agents AGENTS.md .

Prefer adding a nested reference file under an existing skill when the new guidance is really a variant of an existing workflow. Keep a separate top-level skill when separate discovery metadata matters.

Read the full file on GitHub · 245 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. 11d ago First seen · 245 lines · 35 tokens per session scan A 8aecc43b71f6

Subscribe to this mod's changes

writing-skills is a skill published in the GitHub repository EzraApple/skills-init (2 stars, last pushed 1mo ago), licensed MIT. It adds 35 tokens to every session and 1,972 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 2026-08-31.