pyproject.toml Validator

Validate Python project pyproject.toml files against PEP 517/621 rules for project metadata, build system, and tool configurations with detailed reports.

Security Scan

The skill's code and runtime instructions are coherent with its stated purpose (validating pyproject.toml); it requests no credentials, performs only local file parsing/validation, and has no install step.

Purpose & Capability

The name/description, SKILL.md usage examples, and the included Python script all focus on validating pyproject.toml (project, build-system, and tool.*). There are no unrelated binaries, cloud credentials, or unexplained dependencies requested.

Instruction Scope

SKILL.md directs the agent to run the included script against a provided pyproject.toml. The script (as inspected) parses TOML and applies static validation rules; it performs local file reads only and contains no network calls, subprocess execution, or instructions to read unrelated system configuration.

Install Mechanism

No install spec is provided (instruction-only with an included script). That minimizes disk-writing/install risk; the package will simply be run by the agent with Python.

Credentials

The skill declares no required environment variables or credentials, and the script does not reference secrets or external service tokens. Requested access is proportional to its function.

Persistence & Privilege

always is false and the skill is user-invocable; it does not request permanent presence or modifications to other skills or system-wide agent settings.

Assessment

This appears to be a straightforward pyproject.toml validator, but the source is unknown. Before running: (1) review the included script yourself (or run it in a sandbox/container) to confirm it only reads the intended file(s); (2) avoid pointing it at sensitive system files (use the project pyproject.toml); (3) run with a non-privileged user; and (4) prefer running this with a trusted copy of the tool or using a known, published validator if you need stronger provenance guarantees.

Validate pyproject.toml files for Python projects against PEP 517/621 standards.

What it does

Checks your pyproject.toml for common mistakes across three areas:

• [project] — name format (PEP 508), version, license (SPDX), classifiers, dependency specs, authors, dynamic fields
• [build-system] — requires, build-backend validation, known backends
• [tool.*] — ruff, mypy, pytest, black, isort section validation with tool-specific rules

Rules (30+)

Category	Rules	Examples
Project metadata (10)	Missing name/version, invalid name format, unknown fields, malformed requires-python, unknown classifiers, empty authors, name in dynamic	name = "My Package!" → invalid PEP 508 name
Dependencies (4)	Duplicate deps, unpinned deps, overlapping optional groups	requests and Requests both listed
Build system (4)	Missing requires/build-backend, empty requires, unknown fields	No [build-system] table
Tool sections (12+)	Ruff select/ignore overlap, mypy type mismatches, black/ruff conflict, isort/ruff conflict, unusual line lengths, invalid target versions	[tool.ruff.lint] select = ["E501"] + ignore = ["E501"]

Output formats

• text — human-readable with severity icons (❌ ⚠️ ℹ️)
• json — structured with summary counts
• summary — one-line PASS/WARN/FAIL

Exit codes

• 0 — no errors (warnings/info allowed)
• 1 — errors found (or --strict with any issue)
• 2 — file not found or parse error

Commands

validate

Full validation of all sections.

python3 scripts/pyproject_validator.py validate pyproject.toml
python3 scripts/pyproject_validator.py validate --format json pyproject.toml
python3 scripts/pyproject_validator.py validate --strict pyproject.toml

project

Validate only the [project] table.

python3 scripts/pyproject_validator.py project pyproject.toml

build

Validate only [build-system].

python3 scripts/pyproject_validator.py build pyproject.toml

tools

Validate only [tool.*] sections (ruff, mypy, pytest, black, isort).

python3 scripts/pyproject_validator.py tools --min-severity warning pyproject.toml

Options

Option	Values	Default	Description
--format	text, json, summary	text	Output format
--min-severity	error, warning, info	info	Filter by minimum severity
--strict	flag	off	Exit 1 on any issue

Requirements

• Python 3.11+ (uses tomllib from stdlib)
• Falls back to built-in simple TOML parser on Python 3.10

Examples

# Quick check
python3 scripts/pyproject_validator.py validate pyproject.toml

# CI pipeline
python3 scripts/pyproject_validator.py validate --strict --format summary pyproject.toml

# Check only tool configs
python3 scripts/pyproject_validator.py tools --format json pyproject.toml

# Filter noise
python3 scripts/pyproject_validator.py validate --min-severity warning pyproject.toml