Agent skill

Performance Profiling

by agulli in agulli/atlas-agents

Profile and optimize application performance. An agent skill from agulli/atlas-agents.

MITAuto-check passedDevelopment

Install Performance Profiling

skills CLI
$ npx skills add agulli/atlas-agents --skill performance-profiling -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install agulli/atlas-agents performance-profiling --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/agulli/atlas-agents.git skills-src && mkdir -p .claude/skills && cp -r skills-src/ch09_agent_skills/skills/performance-profiling .claude/skills/performance-profiling && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
performance-profiling
GitHub stars
578
Token cost
~804 tokens
SKILL.md length
298 words
Files
1
Skills in repo
12
Repo updated
First seen
Licence
MIT

At a glance

Profile and optimize application performance. An agent skill from agulli/atlas-agents.

  • Works in 6 steps: Establish a baseline. Before changing… → Read the profiler output. Identify the… → Form ONE hypothesis for why the top… → …
  • Asked to improve speed
  • SKILL.md covers Overview, Process, Common Patterns and Rationalizations, plus 1 more section
  • Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Performance Profiling is an agent skill from agulli/atlas-agents. Profile and optimize application performance. Use when asked to improve speed, reduce latency, fix memory leaks, find bottlenecks, or optimize a slow function or endpoint.

Its SKILL.md is about 800 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts. Compatibility notes: Requires python 3.10+ or node 18+

It sits in Development, covering Performance optimization. The licence is MIT.

When your agent uses it

  • Asked to improve speed
  • Fix memory leaks
  • Find bottlenecks
  • Optimize a slow function

Example prompts

  • “/performance-profiling”

Requirements

  • Python 3
  • Compatibility (from SKILL.md): Requires python 3.10+ or node 18+

Workflow steps

6 steps, taken from the first numbered list in SKILL.md.

  1. Establish a baseline. Before changing anything, measure the current performance
  2. Read the profiler output. Identify the top 3 functions by cumulative time. Do not optimize anything that is NOT in the top 3 — this is…
  3. Form ONE hypothesis for why the top bottleneck is slow. Common causes, in order of frequency
  4. Apply ONE change. The smallest possible change that addresses the hypothesis. Do not refactor the entire module.
  5. Measure again. Compare against the baseline. Report the improvement as a percentage.
  6. Repeat. If there is still a performance gap, return to step 2 with the updated profile.

What it can do on your machine

Read from SKILL.md and the folder at commit 2b21998. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    No scripts in the folder and no shell commands in SKILL.md (its code samples are python).

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    No URLs in SKILL.md.

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

  • Compatibility

    Requires python 3.10+ or node 18+

    From compatibility in the SKILL.md frontmatter.

Context cost

Performance Profiling loads about 804 tokens when it runs. Until then it costs about 48 tokens; SKILL.md has 298 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~48
When it runs · the whole SKILL.md, loaded when a task matches
~804

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from agulli/atlas-agents at commit 2b21998, republished under its MIT licence (© agulli). 298 words, ~804 tokens.

Download SKILL.mdSave it as .claude/skills/performance-profiling/SKILL.md (or your agent's skills folder).
name
performance-profiling
description
Profile and optimize application performance. Use when asked to improve speed, reduce latency, fix memory leaks, find bottlenecks, or optimize a slow function or endpoint.
compatibility
Requires python 3.10+ or node 18+
license
MIT

Overview

You do not optimize what you have not measured. Every performance investigation starts with a profiler, not a hypothesis.

Process

  1. Establish a baseline. Before changing anything, measure the current performance:

    • For a function: time it with actual production-representative data
    • For an endpoint: measure p50, p95, p99 latency under realistic load
    • For memory: record heap size at start, peak, and end of operation
    python
    import cProfile, pstats, io
    
    pr = cProfile.Profile()
    pr.enable()
    result = slow_function(data)
    pr.disable()
    
    s = io.StringIO()
    ps = pstats.Stats(pr, stream=s).sort_stats('cumulative')
    ps.print_stats(20)  # Top 20 by cumulative time
    print(s.getvalue())
  2. Read the profiler output. Identify the top 3 functions by cumulative time. Do not optimize anything that is NOT in the top 3 — this is Amdahl's Law in practice.

  3. Form ONE hypothesis for why the top bottleneck is slow. Common causes, in order of frequency:

    • N+1 query (calling the database once per item in a loop)
    • Missing index on a frequently queried column
    • Serialization of large objects in a hot path
    • Synchronous I/O blocking an async event loop
    • Unnecessary repeated computation (missing cache)
  4. Apply ONE change. The smallest possible change that addresses the hypothesis. Do not refactor the entire module.

  5. Measure again. Compare against the baseline. Report the improvement as a percentage.

  6. Repeat. If there is still a performance gap, return to step 2 with the updated profile.

Common Patterns

N+1 query fix:

python
# Before: queries once per user
for user in users:
    user.orders = db.query(f"SELECT * FROM orders WHERE user_id={user.id}")

# After: one query for all users
user_ids = [u.id for u in users]
orders = db.query("SELECT * FROM orders WHERE user_id = ANY(%s)", [user_ids])
orders_by_user = defaultdict(list)
for o in orders: orders_by_user[o.user_id].append(o)
for user in users: user.orders = orders_by_user[user.id]

Caching a pure function:

python
from functools import lru_cache

@lru_cache(maxsize=512)
def expensive_computation(input_id: int) -> dict:
    ...

Rationalizations

ExcuseRebuttal
"I know what the bottleneck is without profiling"You don't. Everyone thinks they know. Profile first, always.
"Let me optimize the whole module while I'm here"Scope creep disguised as diligence. Fix the top bottleneck, measure, then decide if more work is needed.
"It's fast enough on my machine"Production data is 100x larger. Profile with production-scale data.

Verification

  • Baseline performance was measured before any change
  • Profiler output was read (not guessed)
  • Only the top bottleneck was targeted
  • Performance was measured after the change and improvement percentage was reported

© agulli, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

Just SKILL.md in ch09_agent_skills/skills/performance-profiling of agulli/atlas-agents.

Open the folder on GitHubat commit 2b21998

Compare with similar skills

Performance Profiling next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Performance Profiling compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Performance Profiling this skillagulli/atlas-agents578—~804Automated safety check: PassMIT
Code Review ChecklistshareAI-lab/learn-claude-code78k5 repos~1.1kAutomated safety check: PassMIT
LLM Torch Profiler Analysissgl-project/sglang37k2 repos~6.4kAutomated safety check: PassApache-2.0
Pycrazyguitar/pysheeet8.2k—~886Automated safety check: PassMIT
Cmux Debugging Guidemanaflow-ai/cmux28k1 repos~1.1kAutomated safety check: PassCustom licence
Electron Heap Snapshot Analysiskeybase/client9.3k—~875Automated safety check: PassBSD-3-Clause

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Categories

Questions about Performance Profiling

What does Performance Profiling do?

Profile and optimize application performance. An agent skill from agulli/atlas-agents. Performance Profiling is an agent skill from agulli/atlas-agents. Profile and optimize application performance.

When should I use Performance Profiling?

Performance Profiling fits situations like: asked to improve speed; fix memory leaks; find bottlenecks; optimize a slow function.

How do I install Performance Profiling in Claude Code?

Run `npx skills add agulli/atlas-agents --skill performance-profiling -a claude-code`. Or copy the skill folder (ch09_agent_skills/skills/performance-profiling in agulli/atlas-agents) into .claude/skills/performance-profiling in your project. Claude Code loads it when a task matches its description.

How do I install Performance Profiling in Codex?

Run `npx skills add agulli/atlas-agents --skill performance-profiling -a codex`. Or copy the skill folder (ch09_agent_skills/skills/performance-profiling in agulli/atlas-agents) into .agents/skills/performance-profiling in your project. Codex loads it when a task matches its description.

Can I use Performance Profiling in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add agulli/atlas-agents --skill performance-profiling -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/performance-profiling, .gemini/skills/performance-profiling, .github/skills/performance-profiling and .opencode/skills/performance-profiling in your project.

What does Performance Profiling need to run?

SKILL.md names no scripts, command-line tools or credentials: Performance Profiling is instructions for the agent only. Our summary lists: Python 3. Compatibility (from SKILL.md): Requires python 3.10+ or node 18+.

Does Performance Profiling access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Performance Profiling safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Performance Profiling use?

Performance Profiling is published under the MIT licence (declared in SKILL.md). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Performance Profiling use?

About 804 tokens (SKILL.md is roughly 3.2k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Performance Profiling?

Skills that share tags, products or a category with Performance Profiling: Code Review Checklist (shareAI-lab/learn-claude-code, 78k stars), LLM Torch Profiler Analysis (sgl-project/sglang, 37k stars), Py (crazyguitar/pysheeet, 8.2k stars) and Cmux Debugging Guide (manaflow-ai/cmux, 28k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Performance Profiling?

agulli (a GitHub user) maintains it in agulli/atlas-agents, which has 578 GitHub stars. The repository holds 12 skills in this directory. The repository was last updated on July 17, 2026.

Source: agulli/atlas-agents on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.