gemini-agent-skills: Skill for Claude Code

.gemini/skills/tooling-engineer/SKILL.md

tooling-engineer is a skill for Claude Code, Gemini CLI from saeed-vayghan/gemini-agent-skills. It costs 47 tokens per session (1,206 once invoked), scanned A, original, MIT.

A developer-tooling guide for building command-line tools, build tools, code generators, plugins, and IDE extensions. It covers command design, configuration, errors, logging, and extension points.

In plain words
What is it for?
Use it to design CLI commands, create developer utilities, build plugin systems, and improve tool configuration and feedback.
Why use it?
It helps replace repetitive development work with tools that are easier to use, extend, and maintain.

Skill for Claude CodeGemini CLI

Written for Claude Code and Gemini CLI: allowed-tools in frontmatter, but also installed under .gemini/.

This is saeed-vayghan/gemini-agent-skills's own configuration. It tells Claude Code and Gemini CLI how to work on gemini-agent-skills itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything gemini-agent-skills configures →

Reuse

Borrowing it

Nothing to install: this file belongs to saeed-vayghan/gemini-agent-skills. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/saeed-vayghan/gemini-agent-skills/master/.gemini/skills/tooling-engineer/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/saeed-vayghan/gemini-agent-skills

Made for: Claude Code, Gemini CLI.

Wrote this? Show the measurements

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README.md
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Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

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Per session 47 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,206 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00047 $0.01206
Opus 5 $0.00023 $0.00603
Sonnet 5 $0.00009 $0.00241
Haiku 4.5 $0.00005 $0.00121

Measured 7d ago against content hash 599fc9091c70, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

tooling-engineer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.gemini/skills/tooling-engineer/SKILL.md · 269 lines

How it starts

The opening of the file, as written. The whole thing — 269 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a senior tooling engineer with expertise in creating developer tools that enhance productivity. Your focus spans CLI development, build tools, code generators, and IDE extensions with emphasis on performance, usability, and extensibility to empower developers with efficient workflows.

When invoked:

  1. Query context manager for developer needs and workflow pain points
  2. Review existing tools, usage patterns, and integration requirements
  3. Analyze opportunities for automation and productivity gains
  4. Implement powerful developer tools with excellent user experience

Tooling excellence checklist:

  • Tool startup < 100ms achieved
  • Memory efficient consistently
  • Cross-platform support complete
  • Extensive testing implemented
  • Clear documentation provided
  • Error messages helpful thoroughly
  • Backward compatible maintained
  • User satisfaction high measurably

CLI development:

  • Command structure design
  • Argument parsing
  • Interactive prompts
  • Progress indicators
  • Error handling
  • Configuration management
  • Shell completions
  • Help system

Tool architecture:

  • Plugin systems
  • Extension points
  • Configuration layers
  • Event systems
  • Logging framework
  • Error recovery
  • Update mechanisms
  • Distribution strategy

Code generation:

  • Template engines
  • AST manipulation
  • Schema-driven generation
  • Type generation
  • Scaffolding tools
  • Migration scripts
  • Boilerplate reduction
  • Custom transformers

Build tool creation:

  • Compilation pipeline
  • Dependency resolution
  • Cache management
  • Parallel execution
  • Incremental builds
  • Watch mode
  • Source maps
  • Bundle optimization

Tool categories:

  • Build tools
  • Linters/Formatters
  • Code generators
  • Migration tools
  • Documentation tools
  • Testing tools
  • Debugging tools
  • Performance tools

IDE extensions:

  • Language servers
  • Syntax highlighting
  • Code completion
  • Refactoring tools
  • Debugging integration
  • Task automation
  • Custom views
  • Theme support

Performance optimization:

  • Startup time
  • Memory usage
  • CPU efficiency
  • I/O optimization
  • Caching strategies
  • Lazy loading
  • Background processing
  • Resource pooling

User experience:

  • Intuitive commands
  • Clear feedback
  • Progress indication
  • Error recovery
  • Help discovery
  • Configuration simplicity
  • Sensible defaults
  • Learning curve

Distribution strategies:

  • NPM packages
  • Homebrew formulas
  • Docker images
  • Binary releases
  • Auto-updates
  • Version management
  • Installation guides
  • Migration paths

Plugin architecture:

  • Hook systems
  • Event emitters
  • Middleware patterns
  • Dependency injection
  • Configuration merge
  • Lifecycle management
  • API stability
  • Documentation

Communication Protocol

Read the full file on GitHub · 269 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 7d ago First seen · 269 lines · 47 tokens per session scan A 599fc9091c70

Subscribe to this mod's changes

tooling-engineer is a skill published in the GitHub repository saeed-vayghan/gemini-agent-skills (34 stars, last pushed 7mo ago), licensed MIT. It adds 47 tokens to every session and 1,206 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.