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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

59%

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SecuritybySnyk

Passed

No findings from the security scan

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tessl review fix ./plugins/AI-Agents-Safe-Coding-Skills/skills/posix-shell-pro/SKILL.md

The canonical home for this skill is posix-shell-pro in administrakt0r/AI-Agents-Safe-Coding-Skills

SKILL.md
Quality
Evals
Security

Quality

Content

38%Weight 40%Scale 1-5

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

The body is rich in concrete POSIX guidance but heavily redundant — the same rules are restated in three to four sections — and organized as a monolithic 295-line reference file with a dangling pointer to a nonexistent playbook. Broken snippet syntax and the absence of any complete worked example further weaken actionability.

Suggestions

Deduplicate: consolidate 'POSIX Constraints', 'Common Pitfalls to Avoid', and 'POSIX-Specific Best Practices' into a single canonical section (each rule currently appears 3-4 times), cutting the body roughly in half.

Fix the dangling reference: either create resources/implementation-playbook.md and move the reference-grade sections (Essential Tools, CI/CD, Migration, Output) into it, or remove the pointer.

Replace broken/pseudocode snippets (the heredoc-less 'Newline-Separated' pattern, 'mktemp() { ... }') with one complete, executable example script demonstrating the core patterns end-to-end with a validate→fix→retry loop (e.g., shellcheck -s sh, fix, re-run).

DimensionReasoningScore

Conciseness

The ~295-line body repeats the same guidance across four sections: 'Quote all variable expansions' appears in Approach, Safety & Security Patterns, and POSIX-Specific Best Practices; 'use [ not [[' appears in POSIX Constraints, Approach, Common Pitfalls, and POSIX-Specific Best Practices; printf-vs-echo and '.'-vs-'source' each appear 3+ times. Much of it (quoting, command -v, traps) is knowledge Claude already has. This is noticeably padded — anchor 2 — though it doesn't explain basic concepts from scratch, so not 1.

2 / 5

Actionability

Many concrete one-liners ('trap 'rm -f "$tmpfile"' EXIT INT TERM', 'shellcheck -s sh *.sh && shfmt -ln posix -d *.sh', 'case $num in *[!0-9]*) exit 1 ;; esac'), but several snippets are broken or pseudocode: the 'Newline-Separated' pattern ends with a dangling '<<EOF' and no heredoc body, and 'mktemp() { ... }' is a literal placeholder. No complete executable script example exists. Fits anchor 3 — concrete guidance present but incomplete, with pseudocode where executable code should be.

3 / 5

Workflow Clarity

No multi-step workflow with validation checkpoints. The 'Migration from Bash to POSIX sh' section lists a rough sequence (checkbashisms assessment → convert arrays/conditionals → incremental testing) but validation is named, not sequenced — there is no validate→fix→retry loop. The Quality Checklist lists validation criteria but is not embedded in any workflow. Fits anchor 3: sequence present, checkpoints missing or implicit. Not capped lower since this is not a destructive/batch-operation skill.

3 / 5

Progressive Disclosure

The body references 'resources/implementation-playbook.md' but no resources/ directory exists in the bundle — a dangling reference. Meanwhile ~300 lines of reference-grade material (Essential Tools, CI/CD Integration, Migration, Output) are inlined monolithically. Section headers provide some structure (above anchor 2's 'no structure'), but content that clearly belongs in separate files is inlined and the single reference is broken, which tips it to anchor 2 rather than 3.

2 / 5

Total

10

/

20

Passed

Description

61%Weight 40%Scale 1-5

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

A reasonably specific, third-person description with good trigger keywords and a distinct niche, but it never states when to use the skill. Adding an explicit 'Use when...' clause with concrete actions would lift it substantially.

Suggestions

Append an explicit trigger clause, e.g. 'Use when writing or reviewing shell scripts that must run on any POSIX shell, migrating bash scripts to portable sh, or validating scripts with dash/ash.'

Replace the capability claims ('Expert in', 'Specializes in') with concrete actions: writes, migrates, validates, and lints POSIX-compliant shell scripts.

Add natural trigger variations users might say: 'portable shell script', '.sh', 'sh-compatible', 'bash --posix mode'.

DimensionReasoningScore

Specificity

The description names the domain concretely ('strict POSIX sh scripting', 'maximum portability across Unix-like systems') and enumerates target shells '(dash, ash, sh, bash --posix)', but offers no concrete actions beyond capability claims ('Expert in', 'Specializes in') — no write/migrate/validate verbs. It fits anchor 3 (domain plus limited concrete detail, not comprehensive) better than anchor 2 because the shell enumeration is genuinely specific.

3 / 5

Completeness

The 'what' is clear (strict POSIX sh scripting for maximum portability), but there is no 'Use when...' clause or equivalent explicit trigger guidance anywhere in the description. Per the rubric guideline, a missing 'Use when' clause caps completeness at 3, matching the anchor 'Has a clear what but when is missing or only weakly implied'.

3 / 5

Trigger Term Quality

Good natural keyword coverage: 'POSIX sh', 'shell scripts', 'portability', 'dash', 'ash', 'sh', 'bash --posix', 'Unix-like systems' — terms users would naturally say. Not 5 because common variations like 'portable shell script', '.sh', or 'migrate bash to sh' are missing.

4 / 5

Distinctiveness Conflict Risk

'Strict POSIX sh' plus the enumerated shells carves a mostly distinct niche separate from general bash-scripting or shell-tooling skills, with only minor overlap risk against a generic 'shell scripting' skill. Not 5 because no explicit trigger phrases further sharpen the boundary.

4 / 5

Total

14

/

20

Passed

Validation

93%

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

CriteriaDescriptionResult

frontmatter_unknown_keys

Unknown frontmatter key(s) found; consider removing or moving to metadata

Warning

Total

15

/

16

Passed

Repository

administrakt0r/AI-Agents-Safe-Coding-Skills

Path

plugins/AI-Agents-Safe-Coding-Skills/skills/posix-shell-pro/SKILL.md

Reviewed

Table of Contents

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