tooling-discovery

tooling-discovery is a skill for Claude Code, Codex from axiomantic/spellbook. It costs 72 tokens per session (682 once invoked), scanned A, original, MIT.

A guide for finding tools that are available for a task, including command-line utilities and MCP servers, which are connections that let an agent use external tools. It checks a registry before recommending anything.

In plain words
What is it for?
Use it to discover tools for a project or technical domain, check whether they are installed, and present their availability and trust level.
Why use it?
It prevents guessing about tools and helps distinguish tools that are actually available from tools that only sound relevant.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to discover tools for a project or technical domain, check whether they are installed, and present their availability and trust level.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/axiomantic/spellbook/tooling-discovery
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 axiomantic/spellbook --skill tooling-discovery
Clone the repo
git clone --depth 1 https://github.com/axiomantic/spellbook

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 tooling-discovery

README.md
[![agentmods](https://agentmods.dev/badge/skills/axiomantic/spellbook/tooling-discovery/github.svg)](https://agentmods.dev/skills/axiomantic/spellbook/tooling-discovery)
Your own site
<a href="https://agentmods.dev/skills/axiomantic/spellbook/tooling-discovery"><img src="https://agentmods.dev/badge/skills/axiomantic/spellbook/tooling-discovery/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 tooling-discovery

Your own site · 80×15
<a href="https://agentmods.dev/skills/axiomantic/spellbook/tooling-discovery"><img src="https://agentmods.dev/badge/skills/axiomantic/spellbook/tooling-discovery.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 72 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 682 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. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high Agent Snooping · line 16
    Skill accesses MCP server configuration files (mcp.json). MCP configs contain server URLs, authentication tokens, and tool definitions — reading them allows the skill to discover and potentially abuse other tool integrations.
    Fix: Remove all code or instructions that read MCP configuration files (mcp.json). MCP server details should be managed by the agent runtime, not read by individual skills.
How audits are shown
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 $0.00072 $0.00682
Opus 5.5 $0.00029 $0.00273
Sonnet 5.5 $0.00014 $0.00136
Haiku 4.5 $0.00007 $0.00068

Measured 1mo ago against content hash 78813e667089, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

tooling-discovery 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.

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.

skills/tooling-discovery/SKILL.md · 82 lines

How it starts

The opening of the file, as written. The whole thing — 82 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Tooling Discovery

Invariant Principles

  1. Registry is source of truth. Only recommend tools that exist in the curated YAML registry. Never fabricate tool entries.
  2. Trust tiers are non-negotiable. Always present trust classification. Tier 4+ tools require explicit risk warnings before recommendation.
  3. Detection before recommendation. Always run the tooling_discover MCP tool to check availability. Do not skip detection and guess.

Workflow

Step 1: Determine Domain Keywords

Extract domain keywords from one of:

  1. User's explicit request (e.g., "what tools exist for Jira integration?")
  2. Current project context (language, framework, key dependencies)
  3. Active feature being developed (technologies mentioned)

Combine into a comma-separated keyword string.

Step 2: Call tooling_discover

tooling_discover(
    domain_keywords="<comma-separated keywords>",
    project_path="<project root or empty for auto-detect>"
)

Step 3: Present Results

Group results by availability and trust:

Available Tools (detected on this system):

  • List tools where available: true, grouped by detection method
  • For each: name, type, trust tier label, description, how detected

Registry Tools (known but not detected):

  • List tools where available: false
  • For each: name, type, trust tier label, description, source URL

Read the full file on GitHub · 82 lines

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 · 82 lines · 72 tokens per session scan A 78813e667089

Subscribe to this mod's changes

tooling-discovery is a skill published in the GitHub repository axiomantic/spellbook (10 stars, last pushed 2d ago), licensed MIT. It adds 72 tokens to every session and 682 once invoked, about $0.0003 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 2026-09-03.