Software Design Creation Skill: Create software design specifications for new features or standalone software. Use when the user needs help turning a brief idea into a concrete design spec by eliciting missing requirements, clarifying scope, defining users and constraints, outlining architecture and interfaces, identifying risks and assumptions, and writing acceptance criteria that developers can later use for planning and implementation.

Software Design Review Skill: Critically review a software design specification and suggest concrete improvements. Use when the user wants to review, critique, audit, evaluate, or strengthen a design spec, technical specification, feature design, architecture proposal, or implementation plan. Focus on clarity, completeness, correctness, feasibility, tradeoffs, risks, assumptions, and actionable recommendations that improve the design without turning the task into code generation or workflow design.

Software Plan Creation Skill: Create delivery plans for software design specifications. Use when the user wants to plan implementation, break a design into delivery phases, create an implementation roadmap, produce a test plan, or structure a TDD approach for a feature. Reads the latest design spec by default and produces a phased plan covering implementation, testing, and documentation, with TDD slices sized to be logically coherent without degenerating into micro-slices.

Software Plan Review Skill: Critically review a software delivery plan and suggest concrete improvements. Use when the user wants to review, critique, audit, evaluate, or strengthen a delivery plan, implementation plan, project plan, phased roadmap, or test plan. Reviews plans produced by the software-plan-creation skill, checking task breakdown quality, sequencing, dependencies, testing strategy, TDD slice design and sizing, design coverage, risks, and actionability. Produces a structured critique with prioritized recommendations.

Software Slice Selection Skill: Mark the just-completed slice or slice batch (if any), update the completed slices list, select the next unfinished execution unit from a delivery plan based on phase ordering and dependency constraints, and report whether more slices remain. Determines slice exhaustion, not full plan completion — does not verify plan-level Definition of Done items. Combines completion tracking with next-work selection in a single step. Reads plans from .stencila/plans/, parses phase and slice structure, validates package references against the codebase, and can normalize overly narrow plan slices by combining adjacent compatible slices into one execution unit.

Software Test Creation Skill: Write failing tests for a TDD slice based on acceptance criteria and codebase conventions. Use when the "red" phase of red-green-refactor requires tests that define expected behavior before implementation exists. Discovers codebase test conventions first, writes test files that compile or parse but fail because the implementation does not yet exist, and reports test metadata. Works with any language or test framework.

Software Test Review Skill: Evaluate the quality of TDD tests against slice acceptance criteria, codebase conventions, and Red-phase execution results, producing a structured review with Accept or Revise recommendations. Use when tests written during the Red phase of red-green-refactor need quality review — checking coverage of acceptance criteria, conformance with codebase test conventions, test quality (naming, assertions, isolation, readability, triviality), edge-case and error-path coverage, and whether Red-phase failures indicate correctly missing implementation. Flags trivial low-value tests that add more maintenance cost than testing value. Discovers codebase conventions independently and produces an actionable review report.

Software Test Execution Skill: Run scoped tests for a TDD slice, determine the appropriate test framework and command, and report structured pass/fail results. Use when tests need to be executed after writing, implementing, or refactoring code. Reads test metadata, discovers the test framework if needed, executes the scoped test command, parses output into structured results, and reports whether tests passed or failed. Handles compilation errors, missing dependencies, timeouts, and works with any language and test framework.

Software Implementation Skill: Write the minimal production code needed to make failing TDD tests pass (Green phase of red-green-refactor). Use when failing tests exist and production code must be written or modified to satisfy them. Reads and interprets failing test output, discovers codebase conventions (module layout, naming, import patterns, error handling, coding style), writes focused production code that satisfies test expectations without over-engineering, integrates new code with existing modules, types, and APIs, handles revision feedback from failed test runs, and verifies implementation compiles or parses before handing off to test execution. Works with any language or framework.

Software Code Review Skill: Evaluate source code for correctness, quality, security, style conformance, and maintainability, producing a structured review report with findings and recommendations. Use when the user wants to review, critique, audit, evaluate, or inspect source code — checking for bugs, logic errors, unhandled error paths, security vulnerabilities, naming and readability issues, complexity, duplication, coupling, testability, and API design. Discovers codebase conventions independently and produces an actionable report with severity-graded findings grouped by category, prioritized recommendations, and open questions.

Software Code Refactoring Skill: Improve production code quality while preserving all existing test behavior. Commonly used for the Refactor phase of TDD red-green-refactor, but applicable to any codebase with tests. Use when production code works but needs cleanup — reducing duplication, improving naming, simplifying complexity, aligning with codebase style, extracting functions or types, or removing dead code. Discovers conventions, applies safe transformations, verifies compilation after each change, and produces a structured summary. Works with any language or framework.