Code Simplifier

Code Simplifier

Simplify only the relevant changed code unless the user explicitly asks for a broader sweep. Preserve behavior, outputs, error semantics, side effects, and public interfaces.

Default to a single-agent simplification pass. Use spawn_agent only when the user explicitly asks for delegation, parallel subagents, or a multi-agent review and the touched scope is broad enough to benefit.

Workflow

1. Identify the scope.

• Prefer the files or hunks changed in the current task.
• If the scope is unclear, inspect the named function, file, or recent diff.
• Avoid unrelated cleanup outside the touched area.

1. Read the project's local conventions.

• Check AGENTS.md, nearby code, formatter and lint rules, and type patterns.
• Match the repository's style instead of forcing a generic one.
• Reuse existing helpers before introducing new abstractions or dependencies.

1. Decide whether to delegate.

• Keep the immediate blocking work local. Form a short plan before spawning anything.
• Do not delegate small, tightly coupled, or urgent blocking work where your next step depends on the answer.
• If the user explicitly asks for parallelism and the work is broad enough, use spawn_agent for bounded subtasks that can run in parallel with your local work.
• Prefer narrow prompts and explicit file or symbol scope over copying the full thread context. Use fork_context only when the subagent truly needs the same conversation history.
• Prefer explorer agents for read-heavy simplification analysis. Reserve worker agents for implementation only when the write scope can be split into disjoint files or modules.

1. Review the code through three simplification lenses.

• Reuse: prefer existing helpers, utilities, and local patterns before adding new abstractions; remove duplication when the shared shape is stable.
• Quality: improve readability, naming, branching, cohesion, and type clarity; preserve logging, validation, and error semantics.
• Efficiency: remove unnecessary work in the touched code such as redundant passes, allocations, awaits, or lookups when the improvement is obvious and behavior stays identical.
• If the lenses conflict, prefer behavioral safety and readability over extra DRYing or micro-optimizations.

1. Simplify with restraint.

• Flatten unnecessary nesting and branching.
• Remove duplication when the shared pattern is stable and improves readability.
• Replace dense one-liners and nested ternaries with explicit control flow.
• Prefer clear names, direct data flow, and small cohesive helpers.
• Keep comments only when they explain non-obvious intent.
• Preserve logging, validation, and error handling behavior.

1. Verify before finishing.

• Re-read the edited paths for behavior drift, async changes, type regressions, and altered edge cases.
• Run the smallest relevant validation available when practical.
• If a "simplification" would change behavior or conflict with project conventions, stop and explain the tradeoff instead of forcing it.

Subagent Strategy

• Apply all three lenses inline by default.
• If the user explicitly asks for subagents and the task is broad enough to benefit, split the review into bounded subtasks instead of asking multiple agents to rewrite the same hunk.
• A strong default is up to three parallel explorer subagents: one for reuse opportunities, one for quality/readability issues, and one for obvious efficiency cleanup in the touched scope.
• Keep the main agent focused on the core simplification: reviewing conventions, checking behavior-sensitive code paths, and preparing the final edit plan while the subagents run.
• Ask each subagent for concrete findings with file or symbol references and a short rationale. Prefer recommendations over patches unless the write scopes are clearly disjoint.
• Call wait_agent sparingly. Only wait when their result is needed for the next step, and do meaningful non-overlapping local work while they run.
• Reuse an existing delegated thread with send_input when a follow-up stays on the same narrow problem; otherwise spawn a new bounded task.
• Use worker subagents only when the user explicitly wants parallel implementation and each worker can own a disjoint write set. Give each worker clear file ownership and tell it not to revert edits made by others.
• If you override the delegated model for a hard simplification review, prefer the current strongest available model for ambiguous or high-risk reasoning; as of 2026-04, prefer gpt-5.5 when available and fall back to gpt-5.4 when it is not.
• Use gpt-5.4-mini only for fast read-heavy scans where latency or cost matters more than depth.
• Let simple passes inherit the current model unless there is a clear reason to override.
• Only merge recommendations that preserve behavior and improve the touched code without widening scope.
• Treat efficiency as a restraint check, not a license for speculative performance work.

Guardrails

• Do not change public APIs, storage formats, or user-visible text unless explicitly requested.
• Do not widen a refactor just because more cleanup is possible.
• Do not optimize for fewer lines at the expense of clarity.
• Do not merge separate concerns into one helper or expression just to be concise.
• Keep existing import, module, and file-organization conventions.
• Do not spawn subagents just because the environment supports them. Use them only for clear, parallelizable subtasks.
• Do not duplicate work between the main agent and subagents.
• Do not ask multiple subagents to produce overlapping edits for the same code unless the user explicitly wants competing proposals.
• Do not keep polling or waiting on subagents by reflex. If you are not blocked, keep working locally.

Good Triggers

• Simplify this code
• Clean up this implementation
• Make this clearer without changing behavior
• Polish the refactor
• Reduce the complexity in this function
• Review this refactor for reuse, quality, and efficiency
• Review this refactor in parallel with subagents
• Use subagents to scan this diff for reuse, quality, and efficiency

Expected Output

• Make the code changes directly when the request is actionable.
• Call out any uncertainty that could affect behavior before editing.
• Summarize only the meaningful simplifications and any validation that was run.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: yz5e
• Source: yz5e/agent-skills
• License: MIT

Install and usage instructions live in the source repository linked above.