cal-ui-skills
Cal's UI design system. Use when building interfaces inspired by Cal's aesthetic - light mode, Inter font, 4px grid.
70
62%
Does it follow best practices?
Impact
Pending
No eval scenarios have been run
Passed
No known issues
Optimize this skill with Tessl
npx tessl skill review --optimize ./skills/cal/SKILL.mdQuality
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.
The description is well-structured with a clear 'Use when' clause and distinctive branding reference to Cal's design system. Its main weakness is the lack of specific concrete actions—it tells Claude the aesthetic parameters but not what it can actually do (e.g., generate components, style pages). Adding more trigger terms and explicit capabilities would strengthen it.
Suggestions
Add specific concrete actions the skill performs, e.g., 'Generates buttons, forms, cards, and layouts following Cal's UI design system.'
Include additional natural trigger terms users might say, such as 'Cal.com', 'components', 'design tokens', 'theme', or 'styling'.
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Names the domain (UI design system) and mentions some specific elements (light mode, Inter font, 4px grid), but doesn't list concrete actions like 'create buttons', 'style forms', or 'generate layouts'. | 2 / 3 |
Completeness | Clearly answers both what ('Cal's UI design system') and when ('Use when building interfaces inspired by Cal's aesthetic - light mode, Inter font, 4px grid') with an explicit 'Use when' clause and trigger conditions. | 3 / 3 |
Trigger Term Quality | Includes some relevant terms like 'UI design system', 'light mode', 'Inter font', '4px grid', and 'Cal's aesthetic', but misses common user terms like 'components', 'styling', 'theme', 'design tokens', or 'Cal.com'. | 2 / 3 |
Distinctiveness Conflict Risk | Highly distinctive due to the specific reference to 'Cal's' design system with concrete identifiers (Inter font, 4px grid, light mode), making it unlikely to conflict with generic UI or other design system skills. | 3 / 3 |
Total | 10 / 12 Passed |
Implementation
50%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
This is a reasonably well-structured design system reference with clear constraints using MUST/SHOULD/NEVER language and specific values in organized tables. Its main weaknesses are the lack of executable code examples (CSS variables, Tailwind config, component snippets) and some redundant reference data that could be split into separate files. Adding implementation examples and trimming repeated information would significantly improve both actionability and conciseness.
Suggestions
Add executable code examples: a CSS custom properties block defining the semantic tokens, a Tailwind config snippet, or a sample component implementation showing the design system in action.
Remove redundant sections — the 'Border Radius Reference' repeats the Borders section scale, and 'Typography Reference' repeats font family info already in the table. Consolidate or remove duplicates.
Split detailed reference tables (full text styles list, detected layout patterns) into a separate REFERENCE.md file, keeping SKILL.md focused on the core constraints and quick-start guidance.
Add a contrast ratio validation step or tool recommendation to make the accessibility MUST constraint (4.5:1 ratio) actionable rather than just declarative.
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The content is mostly efficient with clear tables and MUST/SHOULD/NEVER constraints, but includes some redundant information — the 'Border Radius Reference' section repeats the scale already listed in the Borders section, the 'Typography Reference' section repeats font info, and the 'Detected Layout Patterns' section lists raw data without clear actionable guidance. The text styles table has many one-off entries that could be condensed. | 2 / 3 |
Actionability | The skill provides specific values (hex codes, pixel sizes, font weights) which are concrete, and uses clear MUST/SHOULD/NEVER directives. However, it lacks executable code examples — no CSS snippets, no Tailwind classes, no component code showing how to implement these tokens. For a UI design system skill, copy-paste ready code (e.g., CSS custom properties, Tailwind config) would significantly improve actionability. | 2 / 3 |
Workflow Clarity | The 'When to Apply' section provides clear triggers, and the content is organized by design concern (colors, typography, spacing, etc.), which creates an implicit workflow. However, there's no sequenced process for building a Cal-style interface, no validation steps (e.g., checking contrast ratios), and no guidance on how to compose these constraints together when building a complete UI. | 2 / 3 |
Progressive Disclosure | The content is well-organized with clear section headers and tables, making it scannable. However, it's a fairly long monolithic document that could benefit from splitting detailed reference tables (all text styles, layout patterns) into separate reference files, keeping SKILL.md as a concise overview with links to detailed specs. | 2 / 3 |
Total | 8 / 12 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 — 11 / 11 Passed
Validation for skill structure
No warnings or errors.
- Repository
- ihlamury/design-skills
- Commit
126714e
- Reviewed
Table of Contents
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