Comprehensive spreadsheet creation, editing, and analysis with support for formulas, formatting, data analysis, and visualization. When Claude needs to work with spreadsheets (.xlsx, .xlsm, .csv, .tsv, etc) for: (1) Creating new spreadsheets with formulas and formatting, (2) Reading or analyzing data, (3) Modify existing spreadsheets while preserving formulas, (4) Data analysis and visualization in spreadsheets, or (5) Recalculating formulas
77
Does it follow best practices?
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npx tessl skill review --optimize ./path/to/skillEvaluation — 76%
↑ 1.35xAgent success when using this skill
Validation for skill structure
Discovery
100%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 skill description that excels across all dimensions. It provides comprehensive coverage of capabilities, includes natural trigger terms with file extensions, explicitly states both what the skill does and when to use it with numbered scenarios, and has clear distinctiveness through spreadsheet-specific terminology and file types.
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Lists multiple specific concrete actions: 'creation, editing, and analysis', 'formulas, formatting, data analysis, and visualization', plus five numbered use cases covering creating, reading, modifying, analyzing, and recalculating. | 3 / 3 |
Completeness | Clearly answers both what ('Comprehensive spreadsheet creation, editing, and analysis with support for formulas, formatting, data analysis, and visualization') AND when ('When Claude needs to work with spreadsheets... for:' followed by explicit numbered triggers). | 3 / 3 |
Trigger Term Quality | Excellent coverage of natural terms users would say: 'spreadsheet', 'formulas', 'formatting', 'data analysis', 'visualization', plus file extensions '.xlsx, .xlsm, .csv, .tsv' that users commonly reference. | 3 / 3 |
Distinctiveness Conflict Risk | Clear niche focused specifically on spreadsheets with distinct file type triggers (.xlsx, .xlsm, .csv, .tsv) and spreadsheet-specific terminology (formulas, cells, recalculating) that distinguishes it from general document or data processing skills. | 3 / 3 |
Total | 12 / 12 Passed |
Implementation
77%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
This is a solid, actionable skill with excellent executable code examples and clear workflow guidance including validation steps. The main weaknesses are moderate verbosity in explanatory sections and a monolithic structure that could benefit from splitting detailed reference material (financial standards, checklists) into separate files for better progressive disclosure.
Suggestions
Move the detailed 'Requirements for Outputs' section (financial model color coding, number formatting standards) to a separate FINANCIAL_MODELS.md reference file
Remove explanatory text Claude already knows, such as 'pandas which provides powerful data manipulation capabilities' and the Library Selection best practices section
Consider extracting the Formula Verification Checklist to a separate VERIFICATION.md file and linking to it from the main workflow
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The skill contains useful information but includes some redundant explanations (e.g., explaining what pandas does, library selection guidance Claude already knows). The financial model color coding and formatting standards are detailed but appropriate for domain-specific knowledge Claude may not have. | 2 / 3 |
Actionability | Provides fully executable Python code examples for all major operations (reading, writing, creating, editing Excel files). The code is copy-paste ready with proper imports and realistic usage patterns. The recalc.py command examples are concrete and specific. | 3 / 3 |
Workflow Clarity | Clear 6-step workflow with explicit validation checkpoint (step 6 for error verification). The recalc.py output interpretation section provides a feedback loop for fixing errors. The Formula Verification Checklist adds structured validation for complex operations. | 3 / 3 |
Progressive Disclosure | Content is reasonably organized with clear sections, but it's a long monolithic document (~200 lines) that could benefit from splitting detailed sections (financial model standards, formula verification checklist) into separate reference files. No external file references are provided. | 2 / 3 |
Total | 10 / 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.
Table of Contents
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