ten-percent-delete

ten-percent-delete is a skill for Claude Code from dormstern/forge. It costs 84 tokens per session (1,039 once invoked), scanned A, original, MIT.

A release-planning rule that requires proposing the removal of at least 10 percent of planned work. Candidates include unused features, ownerless requests, obsolete technical debt, dead code paths, and untouched settings.

In plain words
What is it for?
Reviewing release scope, finding low-use or abandoned work, and creating a kill list of features, code, or settings that should be removed.
Why use it?
It limits the buildup of features and code that nobody needs but the team still has to maintain. It also makes the team explain the evidence when nothing qualifies for removal.

Skill for Claude Code

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

Part of the forge plugin — 10 skills, 15 commands, 9 agents, 1 hook shipped together

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.

agentmods
npx agentmods add skills/dormstern/forge/ten-percent-delete
Any agent
npx skills add dormstern/forge --skill ten-percent-delete
Clone the repo
git clone --depth 1 https://github.com/dormstern/forge

Made for: Claude Code.

Or install forge, the plugin that ships this one along with the rest of its 10 skills, 15 commands, 9 agents, 1 hook.

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 ten-percent-delete

README.md
[![agentmods](https://agentmods.dev/badge/skills/dormstern/forge/ten-percent-delete.svg)](https://agentmods.dev/skills/dormstern/forge/ten-percent-delete)
Your own site
<a href="https://agentmods.dev/skills/dormstern/forge/ten-percent-delete"><img src="https://agentmods.dev/badge/skills/dormstern/forge/ten-percent-delete.svg" alt="Measured on agentmods" height="20"></a>
Per session 84 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,039 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00084 $0.01039
Opus 5 $0.00042 $0.00519
Sonnet 5 $0.00017 $0.00208
Haiku 4.5 $0.00008 $0.00104

Measured 5d ago against content hash 7a58543e437a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

ten-percent-delete 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 5d 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/ten-percent-delete/SKILL.md · 78 lines

How it starts

The opening of the file, as written. The whole thing — 78 lines — stays where its author put it; the contents beside it link to each section on GitHub.

The 10% Delete Rule

Every SHAPE proposes killing at least 10% of the release scope. Not optional. Not "if convenient." Not "if I can find anything."

Why

Products accumulate features the way attics accumulate boxes. The longer you ship, the more drag your product carries — features nobody uses but everyone has to maintain, code paths nobody owns, edge cases that exist for one user from 2024.

The rule forces every release to interrogate product shape. If you can't find 10% to kill, you're not looking hard enough or you've never been honest with the data.

What qualifies for the kill list

In order of how easy they are to spot:

  1. Features with post_mvp_status: "evaluate" and no growth in usage signals across 2 releases. They've earned a verdict.
  2. Features with no requested_by owner. Anonymous features are deletion candidates by default.
  3. Tech debt that's never going to be paid because the feature it underpins isn't valuable. Kill the feature; the debt vanishes.
  4. Edge-case branches in code paths that haven't fired in production for 90 days. If your audit log has 0 events for that path, it's dead code, not a feature.
  5. Settings/toggles nobody changes. A toggle nobody flips is a hidden cost — cognitive load on every PR review.
  6. Features that contradict NEVER. They shouldn't exist. Use the kill list to remove them.
  7. Features that lost the bake-off. If you A/B tested and lost, kill the loser. Don't keep both.

What doesn't qualify

  • Features users like that you don't like.
  • Features that might be useful "someday."
  • Features blocked on external dependencies (those go in progress.md Open Questions, not kill list).
  • Features that are technically working but feel ugly. (Ugly ≠ deletable.)

How /forge:shape enforces it

When /forge:shape runs, the orchestrator:

  1. Scans features.json for post_mvp_status: "evaluate" items, low-signal items, no-owner items, contract-violation items.
  2. Cross-references against releases.json signals (low engagement / negative signals → stronger kill candidate).
  3. Renders the kill list in the SHAPE hero card with reasons (≤6 words each).
  4. Computes the kill ratio (kill list / total in-flight scope).
  5. If <10%, refuses to proceed until the user either expands the list or explicitly states "no candidates qualify and here's the evidence."

Read the full file on GitHub · 78 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. 5d ago First seen · 78 lines · 84 tokens per session scan A 7a58543e437a

Subscribe to this mod's changes

ten-percent-delete is a skill published in the GitHub repository dormstern/forge (6 stars, last pushed 3mo ago), licensed MIT. It adds 84 tokens to every session and 1,039 once invoked, about $0.0004 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.

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