Review Idioms

Review the codebase for non-idiomatic language usage, then file each finding as a Linear issue.

Overview

This skill dispatches a deep codebase analysis focused exclusively on non-idiomatic code — patterns that work but don't follow the conventions and idioms of the language being used. Each finding is documented with code snippets showing both the non-idiomatic pattern and the idiomatic alternative, then filed as a Linear issue.

Workflow

Phase 1: Gather Linear Context

Before reviewing code, collect the Linear team, project, and user information.

1. Fetch all data in parallel using mcp__claude_ai_Linear__list_teams, mcp__claude_ai_Linear__list_projects,

mcp__claude_ai_Linear__list_users, and mcp__claude_ai_Linear__list_issue_labels.

1. Ask the user all three questions in a single `AskUserQuestion` call with these questions:

• Team: Which team should the issues be created under? (list all teams from step 1). If only one team exists,

auto-select it and skip this question.

• Project: Which project should the issues be assigned to? (list all projects; if results can be filtered by

team, do so after team is known).

• Assignee: Who should the issues be assigned to? (list all users for the team, plus a "No assignee" option).

Important: AskUserQuestion requires at least 2 options per question. If a question would have only 1 option, auto-select that option and omit it from the AskUserQuestion call. If all questions can be auto-selected, skip the AskUserQuestion call entirely and inform the user of the auto-selected values.

1. Check existing labels from the fetched label data for the chosen team. If a label named non-idiomatic does not

already exist, create it using mcp__claude_ai_Linear__create_issue_label:

• non-idiomatic (color: #3498db) — Non-idiomatic language usage

Phase 2: Detect the Project Language

Before dispatching the review agent, identify the primary language(s) used in the codebase by examining file extensions, build files, and project configuration (e.g., build.gradle.kts, package.json, Cargo.toml, go.mod, pyproject.toml). This determines what idiomatic patterns to check for.

Phase 3: Codebase Idiom Review

Dispatch a subagent to review the codebase. Use the feature-dev:code-explorer subagent type for deep analysis.

Idiomatic Code Reviewer Agent: Review all source files for non-idiomatic usage of the detected language(s). Look for patterns such as:

• Code written in the style of a different language (e.g., Java patterns in Kotlin, C patterns in Go, JavaScript

patterns in TypeScript)

• Missing use of language-specific features, constructs, or standard library functions
• Imperative code that could leverage the language's functional or declarative capabilities
• Verbose patterns where the language provides concise alternatives
• Not leveraging the type system effectively (e.g., missing sealed types, union types, enums where appropriate)
• Mutable state where immutable alternatives are idiomatic
• Missing use of the language's concurrency primitives or async patterns
• Verbose error handling where the language provides cleaner idioms

For each finding, produce:

• Title (concise summary)
• Language (which language the finding applies to)
• Description (what the non-idiomatic pattern is)
• Impact (readability, maintainability, or performance consequences)
• Importance (Critical / High / Medium / Low)
• Code snippet showing the non-idiomatic pattern (with file path and line numbers)
• Code snippet showing the idiomatic alternative

Phase 4: Present Findings to User

After the agent completes:

1. Compile all findings into a summary table.
2. Present the summary to the user showing: title, language, importance, and file location for each finding.
3. Ask for confirmation before creating Linear issues: "I found N non-idiomatic patterns. Create all as Linear

issues?"

1. Allow the user to exclude specific findings before filing.

Phase 5: File Linear Issues

For each approved finding, create a Linear issue using mcp__claude_ai_Linear__save_issue with:

title: <concise finding title>
team: <user-selected team>
project: <user-selected project>
assignee: <user-selected assignee, or omit if "No assignee" was chosen>
labels: ["non-idiomatic"]
priority: <mapped from importance: Critical=1, High=2, Medium=3, Low=4>
state: Todo
description: |
  ## Description
  <what the non-idiomatic pattern is and context>

  ## Language
  <language name>

  ## Impact
  <readability, maintainability, or performance consequences>

  ## Importance
  <Critical | High | Medium | Low> - <brief justification>

  ## Non-Idiomatic Code
  **File:** `<file_path>`

<code snippet showing the non-idiomatic pattern>

## Idiomatic Alternative

<code snippet showing the idiomatic version>

After all issues are created, present a final summary with the Linear issue identifiers and links.

Finding Quality Standards

Each finding must meet these criteria before filing:

• Specific: Point to exact code, not vague observations.
• Actionable: Include the idiomatic alternative, not just a complaint.
• Impactful: Explain real consequences for readability or maintainability.
• Non-trivial: Skip pure style preferences (formatting, naming conventions with no clarity impact). Focus on patterns where the idiomatic version is meaningfully clearer, safer, or more maintainable.

Priority Mapping