tools-expert

tools-expert is a skill for Claude Code, Codex from victorgrein/spec-crew. It costs 50 tokens per session (1,326 once invoked), scanned A, original, no licence file.

A guide to choosing CrewAI's built-in tools and building custom tools for AI agents. It covers tool chains, input checking, dependencies, caching, asynchronous work, and tests.

In plain words
What is it for?
Use it when selecting CrewAI tools, composing agent toolchains, or creating custom tools with BaseTool or @tool.
Why use it?
It helps developers decide how agent tools should fit together and what a production-ready custom tool needs.

Skill for Claude CodeCodex

Which agent this was written for is unclear — body not stored (licence); the path alone says nothing.

Good fit Use it when selecting CrewAI tools, composing agent toolchains, or creating custom tools with BaseTool or @tool.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/victorgrein/spec-crew/tools-expert
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add victorgrein/spec-crew --skill tools-expert
Clone the repo
git clone --depth 1 https://github.com/victorgrein/spec-crew

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for tools-expert

README.md
[![agentmods](https://agentmods.dev/badge/skills/victorgrein/spec-crew/tools-expert/github.svg)](https://agentmods.dev/skills/victorgrein/spec-crew/tools-expert)
Your own site
<a href="https://agentmods.dev/skills/victorgrein/spec-crew/tools-expert"><img src="https://agentmods.dev/badge/skills/victorgrein/spec-crew/tools-expert/github.svg" alt="Measured on agentmods" height="20"></a>

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.

agentmods 80×15 button for tools-expert

Your own site · 80×15
<a href="https://agentmods.dev/skills/victorgrein/spec-crew/tools-expert"><img src="https://agentmods.dev/badge/skills/victorgrein/spec-crew/tools-expert.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 50 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,326 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 unknown 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 $0.00050 $0.01326
Opus 5.5 $0.00020 $0.00530
Sonnet 5.5 $0.00010 $0.00265
Haiku 4.5 $0.00005 $0.00133

Measured 1mo ago against content hash 985b54fdb167, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

tools-expert 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 1mo ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/scaffold_custom_tool.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

templates/shared/skills/tools-expert/SKILL.md · 155 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

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. 1mo ago First seen · 155 lines · 50 tokens per session scan A 985b54fdb167

Subscribe to this mod's changes

tools-expert is a skill published in the GitHub repository victorgrein/spec-crew (7 stars, last pushed 8mo ago), with no licence file. It adds 50 tokens to every session and 1,326 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-08-31.

Related

Other skills, from other repositories

feature-dev

Take one new feature slice from idea to reviewed, committed code in a single guided pass — scope it into the smallest shippable slice, build it test-first with strict TDD, review and fix the diff, then commit it. Chains slice → test-driven-development → the built-in /code-review → git-commit. Not for reviewing an…

thoughtbot/rails-consultant · 83 tokens

test-driven-development

Strict red-green-refactor TDD workflow for implementing features, fixing bugs, or changing behavior in Rails applications. Enforces the discipline of writing a failing test before any production code. Use whenever you want to implement with TDD — whether a new feature, a bugfix, a refactor, or any behavior change.

thoughtbot/rails-consultant · 68 tokens

phx-work

Execute Elixir/Phoenix plan tasks with progress tracking. Use after phx-plan to implement features with mix compile and mix test verification after each step, or --continue to resume interrupted work.

oliver-kriska/claude-elixir-phoenix · 43 tokens

verify

Verify Elixir/Phoenix changes — compile, format, and test in one loop. Use after implementation, before PRs, or after fixing bugs.

oliver-kriska/claude-elixir-phoenix · 33 tokens

codex-ab

Run an A/B codex review experiment — holistic codex review vs 3 focused dimension passes (security, ecto, liveview) on the branch diff, classify findings, report a panel-value verdict. Use when the branch is fresh, before any codex review runs.

oliver-kriska/claude-elixir-phoenix · 60 tokens

lab:autoresearch

Self-improving loop for plugin skills. Reads program.md, proposes one mutation per iteration, evaluates against deterministic scorer, keeps improvements via git, reverts failures. Targets weakest skill+dimension. Use with /loop for overnight runs.

oliver-kriska/claude-elixir-phoenix · 52 tokens