verification-before-completion

verification-before-completion is a skill for Claude Code from MadAppGang/magus. It costs 47 tokens per session (1,693 once invoked), scanned B, a copy of verification-before-completion, MIT.

A completion-checking rule that requires fresh evidence, such as command output, test results, or a screenshot, before declaring work finished.

In plain words
What is it for?
Use it before marking tasks done, reporting bugs as fixed, preparing commits, or confirming configuration and interface changes.
Why use it?
It reduces unsupported claims that a fix, feature, or commit is complete when it has not been checked after the latest change.

Skill for Claude Code

Written for Claude Code: user-invocable in frontmatter.

Part of the dev plugin — 18 skills, 14 commands, 13 agents shipped together

Good fit Use it before marking tasks done, reporting bugs as fixed, preparing commits, or confirming configuration and interface changes.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/madappgang/magus/verification-before-completion
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 MadAppGang/magus --skill verification-before-completion
Clone the repo
git clone --depth 1 https://github.com/MadAppGang/magus

Made for: Claude Code.

Or install dev, the plugin that ships this one along with the rest of its 18 skills, 14 commands, 13 agents.

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 verification-before-completion

README.md
[![agentmods](https://agentmods.dev/badge/skills/madappgang/magus/verification-before-completion.svg)](https://agentmods.dev/skills/madappgang/magus/verification-before-completion)
Your own site
<a href="https://agentmods.dev/skills/madappgang/magus/verification-before-completion"><img src="https://agentmods.dev/badge/skills/madappgang/magus/verification-before-completion.svg" alt="Measured on agentmods" height="20"></a>
Per session 47 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,693 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 2 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 91% copy Near-identical to another mod 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 $0.00047 $0.01693
Opus 5 $0.00023 $0.00847
Sonnet 5 $0.00009 $0.00339
Haiku 4.5 $0.00005 $0.00169

Measured 4d ago against content hash 4bd7b5c401b9, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade B, and why

verification-before-completion scanned grade B with 2 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 4d 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.

Sends data to an external URLmediumData exfiltration

A POST to an outside endpoint may be telemetry or may be exfiltration; either way the mod talks to somewhere, and you should know where.

$ curl -X POST http://localhost:8000/users -d '{"email":"invalid"}'

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

| API changes | API test output or curl result | `curl -X POST ...` |
Origin

This is a copy

91% identical to verification-before-completion — 9 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

plugins/dev/skills/discipline/verification-before-completion/SKILL.md · 228 lines

How it starts

The opening of the file, as written. The whole thing — 228 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Verification Before Completion

Iron Law: "NO COMPLETION CLAIMS WITHOUT FRESH VERIFICATION EVIDENCE"

When to Use

This skill applies whenever you:

  • Mark a todo item as complete
  • Claim a bug is fixed
  • Report a feature is ready
  • State implementation is done
  • Close a task or issue
  • Prepare to commit changes

Red Flags (Violation Indicators)

  • "should be done" / "should work now" (assumed completion)
  • "probably works" / "likely fixed" (uncertainty without verification)
  • "seems to work" / "appears correct" (observation without test)
  • "Great!" / "Perfect!" / "All set!" (celebration without evidence)
  • "I already tested this earlier" (stale evidence)
  • Completion claim without test output shown
  • Completion claim without grep verification for file changes
  • Completion claim without screenshot for UI changes
  • Completion claim without git diff for code changes
  • Completion claim without build logs for configuration changes
  • Completion claim without CI link for deployment changes
  • "Just a small change, no need to verify" (size-based rationalization)

Key Concepts

Fresh Verification Principle

Verification must be fresh (performed after the claimed change) and explicit (evidence shown, not described).

Wrong:

Fixed the login bug in auth.ts. Should be working now.

Correct:

Fixed the login bug in auth.ts line 42:

git diff src/auth.ts:
-  if (user.token == null) {
+  if (user.token === undefined || user.token === null) {

Test output:
✓ should reject undefined token (15ms)
✓ should reject null token (12ms)
✓ should accept valid token (8ms)

Evidence Types by Change Type

Change Type Required Evidence Tool/Method
Logic/algorithm Test output showing pass bun test, pytest, go test
File creation Grep verification or ls output grep -r "pattern" . or ls -la path/
UI/styling Screenshot or video Browser DevTools screenshot
Configuration Build logs showing success npm run build, cargo build
Deployment CI link or deployment logs GitHub Actions URL, kubectl logs
API changes API test output or curl result curl -X POST ...
Data migration Row count or sample query SELECT COUNT(*) FROM ...
Performance fix Benchmark comparison (before/after) hyperfine, go test -bench

Read the full file on GitHub · 228 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. 4d ago First seen · 228 lines · 47 tokens per session scan B 4bd7b5c401b9

Subscribe to this mod's changes

verification-before-completion is a skill published in the GitHub repository MadAppGang/magus (9 stars, last pushed today), licensed MIT. It adds 47 tokens to every session and 1,693 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it B with 2 findings (sends data to an external url, makes network calls). It is 91% identical to verification-before-completion, differing in 9 lines, and is treated as a copy.

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