legacy-modernizer
tessl i github:jeffallan/claude-skills --skill legacy-modernizerUse when modernizing legacy systems, implementing incremental migration strategies, or reducing technical debt. Invoke for strangler fig pattern, monolith decomposition, framework upgrades.
Validation
75%| Criteria | Description | Result |
|---|---|---|
metadata_version | 'metadata' field is not a dictionary | Warning |
license_field | 'license' field is missing | Warning |
frontmatter_unknown_keys | Unknown frontmatter key(s) found; consider removing or moving to metadata | Warning |
body_examples | No examples detected (no code fences and no 'Example' wording) | Warning |
Total | 12 / 16 Passed | |
Implementation
42%This skill has good structural organization with clear progressive disclosure through reference files, but critically lacks actionable, executable content. It reads more like a role description than a practical skill guide - it tells Claude what a legacy modernizer does rather than showing how to actually perform modernization tasks with concrete code, commands, or specific examples.
Suggestions
Add concrete code examples for key patterns (e.g., a strangler fig facade implementation, a feature flag wrapper, a characterization test template)
Replace abstract workflow steps with specific commands or code snippets (e.g., 'Run `npm run test:characterization` to generate golden master files')
Include a concrete example showing input (legacy code snippet) and output (modernized version with adapter pattern)
Remove the role-playing framing and 'Knowledge Reference' section - these add tokens without actionable value
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The skill includes some unnecessary role-playing framing ('15+ years of experience') and verbose sections like 'Knowledge Reference' that list concepts Claude already knows. The core content is reasonably efficient but could be tightened. | 2 / 3 |
Actionability | The skill provides no concrete code examples, commands, or executable guidance. It describes what to do at a high level ('Apply strangler fig pattern') but never shows how. The workflow steps are abstract descriptions rather than actionable instructions. | 1 / 3 |
Workflow Clarity | The 5-step core workflow provides a clear sequence, and the MUST DO/MUST NOT DO constraints mention validation and rollback. However, there are no explicit validation checkpoints within the workflow, no feedback loops for error recovery, and no concrete verification steps. | 2 / 3 |
Progressive Disclosure | The skill effectively uses a reference table with clear one-level-deep links to detailed guidance files, with explicit 'Load When' conditions. The structure separates overview content from detailed references appropriately. | 3 / 3 |
Total | 8 / 12 Passed |
Activation
65%The description has strong trigger terms that developers would naturally use when seeking modernization help, but it inverts the typical structure by leading with 'when' while leaving 'what' implicit. It lacks concrete action verbs describing what the skill actually does (e.g., analyze, plan, refactor, migrate), making it unclear what specific capabilities are offered beyond pattern knowledge.
Suggestions
Add explicit capability statements before the 'Use when' clause, such as 'Analyzes legacy codebases, creates migration roadmaps, implements incremental refactoring strategies.'
Include concrete actions the skill performs: 'Identifies coupling points, generates decomposition plans, scaffolds adapter layers for strangler fig implementations.'
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Names the domain (legacy systems, migration) and mentions some approaches (strangler fig pattern, monolith decomposition, framework upgrades), but lacks concrete actions - it describes patterns/concepts rather than specific actions like 'analyze dependencies', 'create migration plan', or 'refactor modules'. | 2 / 3 |
Completeness | Has a 'Use when...' clause which addresses the 'when', but the 'what does this do' is weak - it only implies capabilities through the trigger scenarios rather than explicitly stating what actions the skill performs. | 2 / 3 |
Trigger Term Quality | Good coverage of natural terms users would say: 'legacy systems', 'migration', 'technical debt', 'strangler fig', 'monolith decomposition', 'framework upgrades' are all terms developers naturally use when discussing modernization work. | 3 / 3 |
Distinctiveness Conflict Risk | Somewhat specific to modernization/migration domain, but terms like 'technical debt' and 'framework upgrades' could overlap with general refactoring or code quality skills. The strangler fig and monolith decomposition terms provide some distinctiveness. | 2 / 3 |
Total | 9 / 12 Passed |
Reviewed
Table of Contents
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