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tf-best-practices

Best-practice authoring guidance AND a read-only policy gate for AWS Terraform generated by a migration skill. Load during any phase that writes a terraform/ directory — first as the "what to emit" posture rules + security-baseline spec, then after writing as the deterministic policy verdict. Read-only: it reports whether the generated Terraform passes; it never edits .tf files, never touches .phase-status.json, and never decides phase completion. Complements (does not replace) terraform fmt/init/validate.

73

Quality

92%

Does it follow best practices?

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SecuritybySnyk

Passed

No findings from the security scan

SKILL.md
Quality
Evals
Security

Quality

Content

88%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.

A well-architected contract document: clear two-part routing, copy-paste executable commands, explicit exit-code-driven feedback loops, and genuine one-level-deep references. Its weaknesses are mild redundancy in restating the read-only boundary and a rule catalog that overlaps the security-posture reference at detail level.

DimensionReasoningScore

Conciseness

The body is dense, table-heavy, and free of concept explanations Claude already knows, but the read-only boundary is restated four-plus times ("verdict producer, never a mutator", "The caller applies the edit; this unit only reports", "it consumes only caller-context signals", plus the description itself), and "Policy rules enforced today" repeats the "variable-driven fails open" caveat per rule. Not 5 because this repetition could be trimmed; not 3 because there is no filler — every section carries contract information.

4 / 5

Actionability

The gate invocation is copy-paste ready (python3 "$PLUGIN_ROOT/.../validate-terraform-policy.py" "$TERRAFORM_DIR" --json "$VERDICT_PATH") with each parameter's ownership documented, the exit-code table maps every outcome to a concrete caller action, and the verdict JSON shape plus a runnable pytest verification command are given. Fully executable guidance for both touchpoints.

5 / 5

Workflow Clarity

The two-touchpoint flow (posture rules before writing, policy gate after) is sequenced via an explicit routing table, and the exit-code section defines a concrete feedback loop: exit 1 → "read violations[], edit the named .tf sites, re-run (caller's retry budget)". Validation checkpoints are explicit and a Verification section with a runnable test command closes the loop.

5 / 5

Progressive Disclosure

Structure is strong: a context-keyed routing table points to the two real one-level-deep references (security-posture-rules.md with its cited "Caller-context signals" anchor present, terraform-validation.md with the fmt→init→validate→policy protocol), and the fixtures path is real per the test script. Not 5 because the ~60-line "Policy rules enforced today" catalog with per-attribute fail-open semantics partially duplicates the gate-enforced sections of references/security-posture-rules.md and reads like detail-level content that could live in the reference with only a rule-name summary inline.

4 / 5

Total

18

/

20

Passed

Description

92%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 tight, contract-style description that names concrete capabilities, an explicit load trigger for both touchpoints, and clear non-goals. The only gap is a few missing natural synonyms (e.g., "IaC", "infrastructure as code") that would broaden trigger-term coverage.

DimensionReasoningScore

Specificity

Multiple concrete capabilities are named — "Best-practice authoring guidance AND a read-only policy gate", "reports whether the generated Terraform passes", "never edits .tf files", "never touches .phase-status.json" — plus an explicit complement boundary against "terraform fmt/init/validate". Coverage of what the unit does and does not do is comprehensive; not score 4 because there are no noticeable gaps in the action inventory.

5 / 5

Completeness

The what is explicit ("authoring guidance AND a read-only policy gate") and the when is explicit with concrete trigger phrasing ("Load during any phase that writes a terraform/ directory — first as ... then after writing as the deterministic policy verdict"). Both halves are answered clearly; no ambiguity to push it down to 4.

5 / 5

Trigger Term Quality

Good natural coverage: "AWS Terraform", "Terraform", ".tf files", "terraform/ directory", "best-practice", "policy gate", "security-baseline". Missing common synonyms like "IaC" or "infrastructure as code" and a plain "Terraform security review" phrasing; not score 5 because synonym coverage is incomplete, and not 3 because the core terms a caller would use are all present.

4 / 5

Distinctiveness Conflict Risk

The niche is precise — read-only policy verdicts for AWS Terraform generated by a migration skill — and it explicitly distinguishes itself from adjacent tooling ("Complements (does not replace) terraform fmt/init/validate") and from the caller's own duties. Minimal overlap risk with a generic terraform skill; the read-only scoping removes ambiguity.

5 / 5

Total

19

/

20

Passed

Validation

100%

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

Validation — 16 / 16 Passed

Validation for skill structure

No warnings or errors.

Repository

aws/agent-toolkit-for-aws

Path

plugins/aws-startup-advisor/skills/tf-best-practices/SKILL.md

Reviewed

Table of Contents

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