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framework-migration-legacy-modernize

Modernize legacy systems incrementally using the strangler fig pattern. Use when replacing components while preserving business operations, test coverage, and integration contracts.

58

Quality

73%

Does it follow best practices?

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tessl review fix ./skills/framework-migration-legacy-modernize/SKILL.md
SKILL.md
Quality
Evals
Security

Quality

Content

56%Weight 40%Scale 1-5

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

The workflow itself is well-sequenced with genuine validation checkpoints and rollback safeguards, and the dispatch prompts carry specific, quantified guidance. But the body is padded with a concept-explanation paragraph and template boilerplate, depends on unspecified subagent types, and inlines everything with no progressive disclosure across files.

Suggestions

Remove the bracketed extended-thinking paragraph (it explains the strangler fig pattern, which Claude already knows) and replace the generic 'Use this skill when / Do not use / Instructions' filler with one or two lines of genuinely scoped trigger guidance.

Make the orchestration executable: verify or define the referenced subagent types, or restructure the steps as prompts Claude can run directly, and add explicit verification commands after each phase instead of only 'Expected output' descriptions.

Move the 13 per-phase prompt templates into one-level-deep reference files (e.g., references/prompts.md or per-phase files) and keep SKILL.md as a lean overview of the five phases, configuration options, and success criteria.

DimensionReasoningScore

Conciseness

The bracketed extended-thinking paragraph explains the strangler fig concept Claude already knows ('named after the tropical fig tree that gradually envelops and replaces its host...'), and the 'Use this skill when / Do not use / Instructions' sections are generic template filler ('Apply relevant best practices and validate outcomes'). The phase prompts themselves are dense and substantive, keeping this at anchor 3 rather than 2.

3 / 5

Actionability

Subagent prompts include concrete details (weighted formula '(Business Value × 0.4) + (Technical Risk × 0.3) + (Quick Win Potential × 0.3)', 'error rate >1%, latency >2x baseline', '5% → 25% → 50% → 100%'), but everything hinges on subagent_type values like 'legacy-modernizer' and 'python-development::python-pro' that are asserted without any existence check or fallback, and no executable commands or verification steps are given. Concrete but incomplete with missing key details, matching anchor 3.

3 / 5

Workflow Clarity

Five phases are clearly sequenced with 'Context from previous' chaining, expected outputs per step, and real validation checkpoints (characterization tests before refactoring, automatic rollback triggers with '24-hour observation periods', 'minimum 30 days at 0% traffic' before decommissioning, plus a success-criteria checklist). Error-recovery loops are only explicit for the rollout phase, so anchor 4 rather than 5.

4 / 5

Progressive Disclosure

No bundle files exist and no references are used anywhere; ~130 lines inline 13 detailed prompt templates that plausibly belong in reference files. Structure via phase headers is present, but content that should be separate is inline, matching anchor 3 rather than 4 where references are 'mostly clear'.

3 / 5

Total

13

/

20

Passed

Description

78%Weight 40%Scale 1-5

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

A strong description: concrete domain, an explicit 'Use when' clause, and a distinctive pattern name that makes conflict risk minimal. The main weaknesses are missing natural synonym triggers (migration, legacy code, monolith) and a when-clause phrased as a condition rather than user cues.

DimensionReasoningScore

Specificity

Lists several concrete actions — 'Modernize legacy systems incrementally using the strangler fig pattern' and 'replacing components while preserving business operations, test coverage, and integration contracts' — but coverage is incomplete (assessment, rollout, and decommissioning activities are not surfaced). Fits anchor 4 (several specific actions, minor gaps) rather than 3 (only 1-2 actions) or 5 (comprehensive).

4 / 5

Completeness

Answers both 'what' (incremental modernization via strangler fig) and 'when' via an explicit 'Use when replacing components while preserving...' clause. The when-clause is concrete but condition-based rather than user-cue-based ('when the user mentions X'), so anchor 4 fits better than anchor 5's 'concrete trigger phrases'.

4 / 5

Trigger Term Quality

Includes natural terms users would say — 'legacy systems', 'modernize', 'strangler fig', 'replacing components' — but misses common synonyms like 'migration', 'legacy code', 'monolith', or 'refactor'. Good coverage with a few natural terms missing, matching anchor 4 rather than the full synonym coverage of anchor 5.

4 / 5

Distinctiveness Conflict Risk

'Strangler fig pattern' plus legacy-system modernization is a clear niche with distinct triggers and minimal overlap with other skills, matching anchor 5 exactly; no broader wording suggests conflict risk warranting a lower score.

5 / 5

Total

17

/

20

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 — 16 / 16 Passed

Validation for skill structure

No warnings or errors.

Repository

rmyndharis/antigravity-skills

Path

skills/framework-migration-legacy-modernize/SKILL.md

Reviewed

Table of Contents

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