tool-registration

tool-registration is a skill for Claude Code, Codex from pvliesdonk/markdown-vault-mcp. It costs 37 tokens per session (1,112 once invoked), scanned A, original, MIT.

A checklist for adding, renaming, or documenting a Model Context Protocol tool. It covers the tool's label, side-effect hints, icon, documentation string, and published documentation entry.

In plain words
What is it for?
Use it when registering or changing an MCP tool and when checking its metadata, documentation, icons, and public import surface.
Why use it?
It helps prevent a tool from working technically while missing the information that coding clients and users need to understand and use it safely.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents); mentions AGENTS.md.

Good fit Use it when registering or changing an MCP tool and when checking its metadata, documentation, icons, and public import surface.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/pvliesdonk/markdown-vault-mcp/tool-registration
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 pvliesdonk/markdown-vault-mcp --skill tool-registration
Clone the repo
git clone --depth 1 https://github.com/pvliesdonk/markdown-vault-mcp

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 tool-registration

README.md
[![agentmods](https://agentmods.dev/badge/skills/pvliesdonk/markdown-vault-mcp/tool-registration/github.svg)](https://agentmods.dev/skills/pvliesdonk/markdown-vault-mcp/tool-registration)
Your own site
<a href="https://agentmods.dev/skills/pvliesdonk/markdown-vault-mcp/tool-registration"><img src="https://agentmods.dev/badge/skills/pvliesdonk/markdown-vault-mcp/tool-registration/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 tool-registration

Your own site · 80×15
<a href="https://agentmods.dev/skills/pvliesdonk/markdown-vault-mcp/tool-registration"><img src="https://agentmods.dev/badge/skills/pvliesdonk/markdown-vault-mcp/tool-registration.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 37 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,112 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 pass 7 Sept 2026
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 $0.00037 $0.01112
Opus 5 $0.00018 $0.00556
Sonnet 5 $0.00007 $0.00222
Haiku 4.5 $0.00004 $0.00111

Measured 10d ago against content hash e865a4ddf6d8, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

tool-registration 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 10d 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

.agents/skills/tool-registration/SKILL.md · 40 lines

How it starts

The opening of the file, as written. The whole thing — 40 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Tool Registration

Tool Registration Checklist

Every MCP tool you register must carry the full set of metadata below — not just the behaviour. A tool that works but lacks a title, hints, or docs is incomplete. When adding or changing a tool, verify each item:

  • Title — a human-readable annotations.title (e.g. "Search Vault"). Title-aware clients (notably VS Code, which honours only title and readOnlyHint among annotations) render this as the tool's label; without it they fall back to the raw machine name. Set it inline in the tool's annotations={...} dict.
  • Behavioural hintsreadOnlyHint, and where they apply destructiveHint / idempotentHint, in the same annotations dict. These describe side effects accurately (a destructive tool must set destructiveHint=True).
  • Icon — an entry wired via register_tool_icons(...) or @mcp.tool(icons=[...]) (see Tool icons).
  • Docstring — a Google-style docstring; FastMCP surfaces it as the tool description and per-parameter docs.
  • Docs entry — a row in your published tools reference (e.g. docs/tools/index.md) so the tool is documented for users (per the Documentation Discipline section in AGENTS.md).
  • Enforcement test — keep a test that enumerates the registered tools and asserts each carries the metadata above (at minimum a non-empty annotations.title). Enumerate the full registry, not just the client-facing listing, so app-only / hidden tools cannot slip past. Such a test turns this checklist into a CI gate: a future tool added without a title fails loudly rather than silently shipping its machine name.

Tool icons

Drop SVG / PNG / ICO / JPEG files into src/markdown_vault_mcp/static/icons/ and bulk-attach them to registered tools via fastmcp_pvl_core.register_tool_icons(mcp, {"tool_name": "filename.svg"}, static_dir=...) at the end of register_tools() — or attach at decoration time with @mcp.tool(icons=[make_icon(STATIC / "x.svg")]) (where STATIC = Path(__file__).parent / "static" / "icons" is a shorthand you define at module level). The scaffold ships an empty static/icons/ directory; commented-out wiring lives in tools.py.

Read the full file on GitHub · 40 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. 10d ago First seen · 40 lines · 37 tokens per session scan A e865a4ddf6d8

Subscribe to this mod's changes

tool-registration is a skill published in the GitHub repository pvliesdonk/markdown-vault-mcp (32 stars, last pushed today), licensed MIT. It adds 37 tokens to every session and 1,112 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 2026-08-30.

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