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.
npx agentmods add skills/matteocervelli/llms/validationnpx skills add matteocervelli/llms --skill validationgit clone --depth 1 https://github.com/matteocervelli/llmsWhat 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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00028 | $0.03048 |
| Opus 5 | $0.00014 | $0.01524 |
| Sonnet 5 | $0.00006 | $0.00610 |
| Haiku 4.5 | $0.00003 | $0.00305 |
Grade A, and why
validation 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 today.
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.
How it starts
The opening of the file, as written. The whole thing — 565 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Feature Validation Skill
Purpose
This skill provides systematic validation of implemented features, ensuring code quality, test coverage, performance, security, and requirement fulfillment before marking work complete.
When to Use
- After implementation and testing are complete
- Before creating pull request
- Before marking feature as done
- When verifying all acceptance criteria met
- Final quality gate before deployment
Validation Workflow
1. Code Quality Validation
Run Quality Checks:
# Format check (Black)
black --check src/ tests/
# Type checking (mypy)
mypy src/
# Linting (flake8, if configured)
flake8 src/ tests/
# All checks together
make lint # If Makefile configured
Quality Checklist:
Refer to quality-checklist.md for comprehensive review
Key Quality Metrics:
- All functions have type hints
- All public functions have docstrings (Google style)
- No files exceed 500 lines
- No lint errors or warnings
- Code formatted with Black
- Type checking passes with mypy
- No code duplication (DRY principle)
- Single responsibility principle followed
Automated Script:
# Use validation script
python scripts/run_checks.py --quality
Deliverable: Quality report with pass/fail
2. Test Coverage Validation
Run Tests with Coverage:
# Run all tests with coverage
pytest --cov=src --cov-report=html --cov-report=term-missing
# Check coverage threshold
pytest --cov=src --cov-fail-under=80
# View HTML coverage report
open htmlcov/index.html
Coverage Checklist:
- Overall coverage ≥ 80%
- Core business logic ≥ 90%
- Utilities and helpers ≥ 85%
- No critical paths untested
- All branches covered
- Edge cases tested
- Error conditions tested
Identify Coverage Gaps:
# Show untested lines
pytest --cov=src --cov-report=term-missing
# Generate detailed HTML report
pytest --cov=src --cov-report=html
Deliverable: Coverage report with gaps identified
What ships with it
3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- today First seen · 565 lines · 28 tokens per session scan A dd2fee526267
validation is a skill published in the GitHub repository matteocervelli/llms (25 stars, last pushed 3mo ago), licensed MIT. It adds 28 tokens to every session and 3,048 once invoked, about $0.0001 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 2026-09-01.
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