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codebase-onboarding

Analyze an unfamiliar codebase and generate a structured onboarding guide with architecture map, key entry points, conventions, and a starter CLAUDE.md. Use when joining a new project or setting up Claude Code for the first time in a repo.

Quality

84%

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SecuritybySnyk

Passed

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SKILL.md
Quality
Evals
Security

Quality

Content

75%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.

A well-structured, actionable skill: concrete detection checklists, full output templates, a clearly phased workflow with verify-don't-guess and flag-unknowns guardrails, and a self-contained single-file layout. The residual weaknesses are minor — some redundancy between description, When-to-Use, and Examples sections, a few non-executable detection steps, no final validation of the generated artifacts, and output templates that could be split into reference files.

Suggestions

Trim redundancy: drop the 'When to Use' bullets that restate the frontmatter description, and reduce the Examples section to one-line action summaries since Phase 4 already fully specifies both outputs.

Make the remaining detection steps executable — give the directory snapshot and git-history checks concrete commands or globs (e.g. `git log --oneline -20`, `find . -maxdepth 2 -type d`) alongside the existing manifest list.

Add a short Phase 5 'Validate' step: re-check the generated guide against the codebase (do the entry points and commands actually exist) and confirm the CLAUDE.md merge preserved pre-existing instructions.

DimensionReasoningScore

Conciseness

The body is almost entirely actionable checklists, detection patterns, and output templates with essentially no explanation of concepts Claude already knows, so it is not the 3 anchor's 'some unnecessary explanation'. Minor trimmable redundancy keeps it below 5: the 'When to Use' section repeats the frontmatter description, and the 'Examples' section restates the two output artifacts already fully specified in Phase 4.

4 / 5

Actionability

Reconnaissance names exact manifests (package.json, go.mod, Cargo.toml...), configs, and entry-point patterns, and both outputs have complete copy-paste-ready markdown templates — matching the 4 anchor. Not 5: a few steps stop short of executable specificity, e.g. 'Directory structure snapshot' and 'Git Conventions' name what to look for but give no command or glob to run.

4 / 5

Workflow Clarity

A clearly sequenced 4-phase workflow (Reconnaissance → Architecture Mapping → Convention Detection → Generate Artifacts) with checkpoint-style guidance ('Verify, don't guess', 'Read existing CLAUDE.md first and enhance', 'Flag unknowns'). No destructive or batch operations, so the validation cap does not apply; the gap keeping it at 4 rather than 5 is the absence of a final validation/review step for the generated artifacts themselves.

4 / 5

Progressive Disclosure

No bundle files exist, and the single-file body is well sectioned with no nested or buried references, matching the 4 anchor ('good structure; most content appropriately placed'). Not 5: the ~90 lines of inline example output templates (Output 1 and Output 2) are content that could live in a reference file, though they are clearly signaled and serve as output formats, so this is a minor organization gap rather than the 3 anchor's misplaced bulk.

4 / 5

Total

16

/

20

Passed

Description

88%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 actions, enumerated deliverables, third-person voice, and an explicit 'Use when' clause covering both join-a-project and set-up-Claude-Code triggers. The main gap is trigger-term breadth — the natural phrases users actually say ("onboard me", "understand this codebase", "generate a CLAUDE.md") live in the body's 'When to Use' section rather than the description where they aid skill routing.

Suggestions

Fold one or two natural user phrasings from the body into the description, e.g. "Use when the user asks to be onboarded to a repo, wants to understand an unfamiliar codebase, or asks to generate a CLAUDE.md."

Sharpen the second trigger to reduce overlap with generic init/CLAUDE.md skills, e.g. "Use when joining a new team's codebase or asked to map an unfamiliar repo's architecture" — distinguishing analysis from plain file generation.

DimensionReasoningScore

Specificity

"Analyze an unfamiliar codebase and generate a structured onboarding guide with architecture map, key entry points, conventions, and a starter CLAUDE.md" lists multiple specific concrete actions with an enumerated set of deliverables, matching the comprehensive-coverage anchor. Not 4: the skill's outputs are fully enumerated rather than having minor gaps; not below since every action named is concrete.

5 / 5

Completeness

The description explicitly answers both questions: the "what" is a structured onboarding guide plus a starter CLAUDE.md, and the "when" is an explicit "Use when joining a new project or setting up Claude Code for the first time in a repo." clause. This matches the 5 anchor; a 4 would require the when-clause to be less explicit or concrete.

5 / 5

Trigger Term Quality

"joining a new project", "setting up Claude Code for the first time in a repo", and "CLAUDE.md" are natural user phrasings, but common variants like "onboard me", "help me understand this codebase", or "walk me through this repo" appear only in the body, not the description. Matches the 4 anchor (good coverage, a few natural terms missing) rather than 5, which requires synonym-level coverage in the description itself.

4 / 5

Distinctiveness Conflict Risk

The onboarding-guide/CLAUDE.md niche is distinct, but "setting up Claude Code for the first time in a repo" overlaps with generic CLAUDE.md-generation or repo-init skills, so minor overlap risk with closely related skills remains. Matches the 4 anchor rather than 5, which demands minimal conflict risk with distinct triggers.

4 / 5

Total

18

/

20

Passed

Validation

93%

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 15 / 16 Passed

Validation for skill structure

CriteriaDescriptionResult

metadata_version

'metadata.version' is missing

Warning

Total

15

/

16

Passed

Repository

affaan-m/ECC

Path

skills/codebase-onboarding/SKILL.md

Reviewed

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