agentmods.dev

mcp-tool

mcp-tool is a skill for Claude Code, Codex from dfridkin/clawops. It costs 0 tokens per session (345 once invoked), scanned A, original, MPL-2.0.

A development procedure for adding a new Model Context Protocol (MCP) tool to the Clawops project. It covers the tool definition, implementation, registration, and tests.

In plain words
What is it for?
Defining tool inputs, writing the handler, registering it in the server, generating schemas, and running type checks and tests.
Why use it?
It provides the required project steps and safeguards so a new tool matches the project's schemas, permissions, and output rules.

Skill for Claude CodeCodex

not rated 1 1mo ago A scan 0 tokens original MPL-2.0
View the source file dfridkin/clawops
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.

agentmods
npx agentmods add skills/dfridkin/clawops/mcp-tool
Any agent
npx skills add dfridkin/clawops --skill mcp-tool
Clone the repo
git clone --depth 1 https://github.com/dfridkin/clawops

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 mcp-tool

README.md
[![agentmods](https://agentmods.dev/badge/skills/dfridkin/clawops/mcp-tool.svg)](https://agentmods.dev/skills/dfridkin/clawops/mcp-tool)
Your own site
<a href="https://agentmods.dev/skills/dfridkin/clawops/mcp-tool"><img src="https://agentmods.dev/badge/skills/dfridkin/clawops/mcp-tool.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 345 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00000 $0.00345
Opus 5 $0.00000 $0.00172
Sonnet 5 $0.00000 $0.00069
Haiku 4.5 $0.00000 $0.00034

Measured 4d ago against content hash b4f36f462c24, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

mcp-tool 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 4d 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.

.claude/skills/mcp-tool/SKILL.md · 35 lines

What it actually says

/mcp-tool

Add a new MCP tool.

Steps

  1. Add the tool to spec/mcp-tools.yaml (source of truth, R-meta-1):

    • Name: clawops_<verb> or clawops_<noun>_<verb>
    • Assign toolset (cli | workflow | read | admin — or array)
    • Write description with "Use when" and "Do NOT use when" (R3)
    • Set ALL four annotations hints (R10): readOnlyHint, destructiveHint, idempotentHint, openWorldHint
    • Define input fields with types and optional/default

  2. Regenerate _generated.ts:

    pnpm gen:schemas

  3. Create the handler in the appropriate toolset subdirectory:

    src/mcp/tools/<toolset>/<tool-name>.ts

  4. Register the handler in src/mcp/server.ts.

  5. Write tests in tests/mcp/tools.test.ts — invoke via in-memory MCP client and assert schema conformance.

  6. Run pnpm typecheck && pnpm test.

Constraints

  • Per .claude/rules/mcp.md: no credentials in inputs (R6), stdio never writes stdout (R15), cap output at 8KB (R14).
  • Destructive tools must trigger elicitation (R19) unless yes: true.
  • Long-running tools (>10s) must emit notifications/progress or return a taskId.
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. 4d ago First seen · 35 lines · 0 tokens per session scan A b4f36f462c24

Subscribe to this mod's changes

mcp-tool is a skill published in the GitHub repository dfridkin/clawops (1 stars, last pushed 1mo ago), licensed MPL-2.0. It costs nothing until one of its globs matches a file; then it loads 345 tokens. 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.

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