developmental-editor

developmental-editor is a skill for Claude Code, Codex from Calliope-Editor/writing-skills. It costs 118 tokens per session (2,739 once invoked), scanned A, original, MIT.

A fiction editor that examines a book’s overall story shape and delivers either a broad manuscript assessment or a detailed developmental edit.

In plain words
What is it for?
Use it to assess a novel, define the critical lens for reviewing it, identify root problems with evidence, and mark the scenes where those problems occur.
Why use it?
It helps authors find structural and story-level problems without rewriting the manuscript for them.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: positional $N argument.

Good fit Use it to assess a novel, define the critical lens for reviewing it, identify root problems with evidence, and mark the scenes where those problems occur.

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Install with agentmods
npx agentmods add skills/calliope-editor/writing-skills/developmental-editor
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 Calliope-Editor/writing-skills --skill developmental-editor
Clone the repo
git clone --depth 1 https://github.com/Calliope-Editor/writing-skills

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 developmental-editor

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

Your own site · 80×15
<a href="https://agentmods.dev/skills/calliope-editor/writing-skills/developmental-editor"><img src="https://agentmods.dev/badge/skills/calliope-editor/writing-skills/developmental-editor.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 118 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,739 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 $0.00118 $0.02739
Opus 5 $0.00059 $0.01370
Sonnet 5 $0.00024 $0.00548
Haiku 4.5 $0.00012 $0.00274

Measured 9d ago against content hash 1acc122396ec, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

developmental-editor 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 9d 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/editorial/developmental-editor/SKILL.md · 227 lines

How it starts

The opening of the file, as written. The whole thing — 227 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Diagnose the shape of the story and deliver the service a developmental editor actually sells — an assessment or a full edit letter — after declaring the lens the diagnosis will use.

The one rule

This skill reads, analyses, and critiques. It never writes or rewrites the author's prose. It will point at the chapter that collapses the midpoint and explain why; it will not hand back a rewritten chapter. The diagnosis is the deliverable — the writing stays the author's.

The service

Two tiers, mirroring how the trade actually sells this work (EFA's service taxonomy). The dollar figures are approximate — 2026 EFA/Reedsy survey medians, there to set expectations of depth, not to quote a market:

  • Manuscript assessment — the overall critique: context profile, declared lens, the two or three root diagnoses with evidence, genre calibration, open questions. The ~$600–$2,000 service.
  • Full developmental edit — everything in the assessment, plus the complete edit letter in craft-category sections and a scene-anchored flag list at the exact places the problems live. The ~$2,400–$4,200 service for an 80k novel.

The writer picks at intake. Book coaching — developing a book that isn't drafted yet — is a different service, and out of scope here.

Try it

You don't need the jargon — the editor settles the details at intake. Openers that work:

  • "Here's my finished draft and a one-line premise — is the story working?"
  • "The middle drags and I can't figure out why. Can you do an assessment?"
  • "It's a quiet, Austen-ish novel — judge the shape it's going for, not the plot it 'should' have." (declare intent)

Input

Pasted text, an attached manuscript file, or a named range ("read chapters 4–9") — no tool, plugin, or account assumed. The assessment works on partials; the full edit letter wants the whole draft. Either way it diagnoses what it was given and says what it couldn't see.

Intake — what a real editor asks first

Settle these before reading. Ask only what the submission and conversation don't already answer; infer the rest and declare it:

Read the full file on GitHub · 227 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. 9d ago First seen · 227 lines · 118 tokens per session scan A 1acc122396ec

Subscribe to this mod's changes

developmental-editor is a skill published in the GitHub repository Calliope-Editor/writing-skills (2 stars, last pushed 1mo ago), licensed MIT. It adds 118 tokens to every session and 2,739 once invoked, about $0.0006 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.