azure-image-builder

Build Azure managed images and Azure Compute Gallery images with Packer. Use when creating custom images for Azure VMs.

1.25x

Quality

70%

Does it follow best practices?

Impact

100%

1.25x

Average score across 3 eval scenarios

Securityby

Passed

No known issues

Optimize this skill with Tessl

npx tessl skill review --optimize ./packer/builders/skills/azure-image-builder/SKILL.md

Quality

Discovery

75%

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

This is a competent description that clearly identifies its niche (Packer-based Azure image building) and includes an explicit 'Use when' clause. Its main weakness is that it could list more specific actions and include additional trigger terms that users might naturally use when requesting this type of work.

Suggestions

Add more specific actions such as 'configure provisioners, define HCL build templates, publish to shared image galleries'

Expand trigger terms to include common variations like 'VM image', 'golden image', '.pkr.hcl', 'packer build', 'image builder'

Dimension	Reasoning	Score
Specificity	Names the domain (Azure images with Packer) and two specific types of outputs (managed images, Compute Gallery images), but doesn't list more granular actions like configuring provisioners, defining build templates, or publishing to galleries.	2 / 3
Completeness	Clearly answers both 'what' (build Azure managed images and Compute Gallery images with Packer) and 'when' (Use when creating custom images for Azure VMs), with an explicit 'Use when' clause.	3 / 3
Trigger Term Quality	Includes good keywords like 'Azure', 'Packer', 'managed images', 'Compute Gallery', and 'custom images', but misses common variations users might say such as 'VM image', 'image builder', 'HCL template', 'packer build', '.pkr.hcl', or 'golden image'.	2 / 3
Distinctiveness Conflict Risk	The combination of Packer + Azure image building is a very specific niche that is unlikely to conflict with other skills. The mention of both 'managed images' and 'Compute Gallery images' further narrows the scope.	3 / 3
	Total	10 / 12 Passed

Implementation

64%

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

A solid, actionable skill with complete, executable HCL templates and clear authentication guidance for Azure image building with Packer. Main weaknesses are the lack of explicit validation/verification steps in the workflow (important given the cost and time involved) and some redundancy in the authentication sections. The content could benefit from tighter organization and post-build verification guidance.

Suggestions

Add explicit validation and verification steps: after `packer build`, show how to verify the image was created (e.g., `az image list` or `az sig image-version list`) and what to do if the build fails.

Remove the duplicate authentication environment variable exports — they appear in both the Authentication and Build Commands sections.

Consider extracting the full managed image template into a referenced example file, keeping only a minimal snippet inline to reduce the skill's token footprint.

Dimension	Reasoning	Score
Conciseness	Generally efficient with good code examples, but includes some redundancy (authentication env vars shown twice, the note about costs is unnecessary context Claude doesn't need). The variable declarations for client_id/client_secret/subscription_id/tenant_id add bulk that could be trimmed since Claude knows how to declare Packer variables.	2 / 3
Actionability	Provides fully executable HCL templates for both managed images and Compute Gallery, concrete bash commands for authentication setup and build execution, and specific Azure image references (publisher, offer, SKU). All code is copy-paste ready.	3 / 3
Workflow Clarity	The Build Commands section shows a clear sequence (init → validate → build), but there's no explicit validation checkpoint or feedback loop — e.g., what to do if `packer validate` fails, or how to verify the built image works. For a process that takes 15-45 minutes and incurs costs, missing verification steps are notable.	2 / 3
Progressive Disclosure	Content is reasonably structured with clear sections, but the full managed image template (~60 lines) is inline when it could be referenced. References at the bottom are good, but the skill is somewhat monolithic for its length. No separation of basic vs advanced content into linked files.	2 / 3
	Total	9 / 12 Passed

Validation

100%

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 — 11 / 11 Passed

Validation for skill structure

No warnings or errors.

Repository: hashicorp/agent-skills
Commit: b129bb5

Reviewed: 11 days ago

Table of Contents

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