cost-projection
Project the monthly cost of an infrastructure definition (Terraform, CDK, CloudFormation, SAM) using CloudZero spend data. Reads IaC files, enumerates resources, and produces a line-item cost breakdown.
61
72%
Does it follow best practices?
Impact
—
No eval scenarios have been run
Advisory
Suggest reviewing before use
Optimize this skill with Tessl
npx tessl skill review --optimize ./plugins/cost-analyst/skills/cost-projection/SKILL.mdQuality
Discovery
82%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 strong description with excellent specificity, naming concrete IaC tools and specific actions (reading files, enumerating resources, producing line-item breakdowns). The main weakness is the absence of an explicit 'Use when...' clause, which means Claude must infer when to select this skill rather than being explicitly guided. The domain is distinctive enough that conflicts with other skills are unlikely.
Suggestions
Add an explicit 'Use when...' clause, e.g., 'Use when the user asks to estimate, project, or forecast infrastructure costs from Terraform, CDK, CloudFormation, or SAM templates.'
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Lists multiple specific concrete actions: 'project monthly cost', 'reads IaC files', 'enumerates resources', 'produces a line-item cost breakdown'. Also names specific IaC formats (Terraform, CDK, CloudFormation, SAM). | 3 / 3 |
Completeness | Clearly answers 'what does this do' (projects monthly cost, reads IaC files, enumerates resources, produces cost breakdown), but lacks an explicit 'Use when...' clause or equivalent trigger guidance. The when is only implied by the description of capabilities. | 2 / 3 |
Trigger Term Quality | Includes strong natural keywords users would say: 'cost', 'Terraform', 'CDK', 'CloudFormation', 'SAM', 'infrastructure', 'IaC', 'monthly cost', 'cost breakdown'. These cover the major IaC tools and cost-related terms users would naturally use. | 3 / 3 |
Distinctiveness Conflict Risk | Highly distinctive niche combining IaC cost projection with CloudZero spend data. The specific mention of Terraform/CDK/CloudFormation/SAM plus cost estimation creates a clear, unique trigger profile unlikely to conflict with other skills. | 3 / 3 |
Total | 11 / 12 Passed |
Implementation
62%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
This is a highly actionable and well-structured skill with an excellent 7-phase workflow, concrete commands, and a thorough output template. However, it suffers significantly from verbosity — it explains IaC syntax Claude already understands, includes inline content that should be in referenced files, and over-specifies discovery heuristics. The progressive disclosure structure exists (7 reference files) but isn't leveraged enough, leaving the main file bloated.
Suggestions
Move the estimation formulas table, pricing lookup examples, and the full output report template to referenced files (e.g., service-mapping.md and cost-projection-output-examples.md are already referenced — use them instead of duplicating content inline).
Remove explanations of IaC syntax (what Terraform resource blocks look like, what CDK construct instantiations look like, what CloudFormation Resources sections look like) — Claude already knows these formats.
Consolidate the 5-step auto-discovery process into a concise checklist rather than showing every grep/find command; move the detailed commands to a reference file.
Remove or drastically shorten the 'File Pattern → Framework' table and IaC parsing examples — a single sentence like 'Detect framework from file extensions and imports, then extract resource types, names, and cost-relevant configuration' suffices.
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The skill is extremely verbose at ~400+ lines. It over-explains discovery heuristics (5 sub-steps for auto-discovery), includes lengthy estimation tables Claude could look up, explains what CDK/Terraform/CloudFormation resource blocks look like (Claude already knows), and repeats security/best-practice guidance that could be in referenced files. Significant token waste. | 1 / 3 |
Actionability | The skill provides highly concrete, executable guidance throughout: specific bash commands for file discovery, exact API call parameters (group_by, filters, granularity), web search query templates, pricing formulas with specific numbers, and a complete output template with example values. Copy-paste ready at every step. | 3 / 3 |
Workflow Clarity | The 7-phase workflow is clearly sequenced with explicit goals for each phase. Phase 3 includes validation steps (confirming dimension values exist in CloudZero), Phase 4 specifies how to calculate run rates, Phase 5 has a prioritized strategy cascade (web lookup → similar resources → fallback formulas), and Phase 6 has explicit aggregation logic. Confidence levels serve as validation checkpoints for estimates. | 3 / 3 |
Progressive Disclosure | The skill references 7 external files in 'See Also' and uses ${CLAUDE_PLUGIN_ROOT}/references/ paths throughout, which is good structure. However, the main SKILL.md itself is monolithic — the estimation formulas table, the full output template, the 5-step auto-discovery process, and the IaC parsing details could all be in referenced files. Too much detail is inline rather than delegated to the referenced documents. | 2 / 3 |
Total | 9 / 12 Passed |
Validation
90%Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.
Validation — 10 / 11 Passed
Validation for skill structure
| Criteria | Description | Result |
|---|---|---|
frontmatter_unknown_keys | Unknown frontmatter key(s) found; consider removing or moving to metadata | Warning |
Total | 10 / 11 Passed | |
- Repository
- Cloudzero/cloudzero-claude-marketplace
- Commit
760a9c7
- Reviewed
Table of Contents
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