posix-shell-pro

Expert in strict POSIX sh scripting for maximum portability across Unix-like systems. Specializes in shell scripts that run on any POSIX-compliant shell (dash, ash, sh, bash --posix).

Quality

50%

Does it follow best practices?

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Quality

Content

50%Weight 40%Scale 1-3

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

The content is highly actionable with concrete POSIX patterns, but it is verbose and heavily redundant across sections, and it monolithically inlines material that would benefit from being split into separate reference files. Workflow sequencing for migration lacks explicit validation checkpoints.

Suggestions

Deduplicate the repeated POSIX prohibitions (no arrays, no [[, quote variables, use printf, use '.') into a single canonical section and reference it elsewhere.

Split advanced techniques, migration, and CI/CD into separate referenced files (e.g., MIGRATION.md, CI.md) to reduce the monolithic body.

Add explicit validation checkpoints to the migration workflow (e.g., 'Run shellcheck -s sh and dash after each converted function before proceeding').

Dimension	Reasoning	Score
Conciseness	The ~295-line body heavily repeats the same prohibitions across 'POSIX Constraints', 'Common Pitfalls to Avoid', and 'POSIX-Specific Best Practices' (no arrays/[[/local, quote variables, use printf, use '.', use case), padding the token budget with content Claude already knows.	1 / 3
Actionability	It provides numerous copy-paste-ready, executable patterns such as `trap 'rm -f "$tmpfile"' EXIT INT TERM`, `case $num in [!0-9]) exit 1 ;; esac`, and `command -v cmd >/dev/null 2>&1`, fitting 'Fully executable code/commands; copy-paste ready'.	3 / 3
Workflow Clarity	The 'Migration from Bash to POSIX sh' section lists a sequence (assessment, array elimination, conditional updates, testing) but validation checkpoints are only implicit ('continuous validation'), and most of the body is reference material rather than a sequenced workflow with feedback loops.	2 / 3
Progressive Disclosure	Sections are clearly headed and organized, but the body is a monolithic ~295-line wall with no bundle files; advanced techniques, migration, and CI/CD content that should be split into separate reference files is inline, matching 'Some structure but could be better organized'.	2 / 3
	Total	8 / 12 Passed

Description

50%Weight 40%Scale 1-3

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

The description clearly identifies the POSIX sh portability niche with concrete shell names, but it lacks an explicit 'Use when...' trigger and does not enumerate concrete actions. It is solid but generic enough to cap most dimensions at the middle level.

Suggestions

Add an explicit 'Use when...' clause naming natural triggers, e.g. 'Use when writing shell scripts that must run on dash/ash/sh, migrating bash to POSIX sh, or maximizing portability across Unix systems.'

Enumerate concrete actions (write, test, lint, migrate, debug) instead of only 'Expert in' / 'Specializes in'.

Include more common user phrasings like 'shell script', 'portable shell script', and 'shellcheck' as trigger terms.

Dimension	Reasoning	Score
Specificity	Names the domain ('strict POSIX sh scripting') and some actions ('scripting', 'run on any POSIX-compliant shell') but does not enumerate concrete actions like writing, testing, migrating, or debugging; matches the 'Names domain and some actions, but not comprehensive' anchor.	2 / 3
Completeness	It clearly answers 'what' (POSIX sh scripting for portability) but provides no 'Use when...' or equivalent explicit trigger guidance for when to use the skill, which caps completeness at 2 per the judging guidelines.	2 / 3
Trigger Term Quality	Relevant terms are present ('POSIX sh', 'dash', 'ash', 'sh', 'bash --posix') but common user variations like 'shell script', 'portable shell', or 'shellcheck' are missing, fitting 'Some relevant keywords but missing common variations'.	2 / 3
Distinctiveness Conflict Risk	'Strict POSIX sh' with named shells is a fairly distinct niche, but it could still overlap with general shell-scripting or bash skills, matching 'Somewhat specific but could still overlap with similar skills'.	2 / 3
	Total	8 / 12 Passed

Validation

93%

Warnings & errors only

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 15 / 16 Passed

Validation for skill structure

Criteria	Description	Result
metadata_version	'metadata.version' is missing	Warning

	Total	15 / 16 Passed

Repository: rmyndharis/antigravity-skills
Path: skills/posix-shell-pro/SKILL.md
Commit: e63f7dd

Reviewed: 13 days ago

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