What is mcp-verifier?

A verification tool for the webcake-landing MCP server, a program that communicates with coding agents through the Model Context Protocol. It checks whether a source change builds, starts, and follows the project's conventions.

Use it after editing the server's source to run its build and smoke tests, confirm the runtime schema is included, check startup output, and inspect source conventions.

It catches missing generated files, startup failures, incorrect output handling, and import problems before a change is considered complete.

How vuluu2k/webcake-landing-mcp configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to vuluu2k/webcake-landing-mcp. 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/vuluu2k/webcake-landing-mcp/main/.claude/agents/mcp-verifier.md

Clone the repo

git clone --depth 1 https://github.com/vuluu2k/webcake-landing-mcp

Made for: Claude Code.

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.

README.md

[![agentmods](https://agentmods.dev/badge/agents/vuluu2k/webcake-landing-mcp/mcp-verifier/github.svg)](https://agentmods.dev/agents/vuluu2k/webcake-landing-mcp/mcp-verifier)

Your own site

<a href="https://agentmods.dev/agents/vuluu2k/webcake-landing-mcp/mcp-verifier"><img src="https://agentmods.dev/badge/agents/vuluu2k/webcake-landing-mcp/mcp-verifier/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.

Your own site · 80×15

<a href="https://agentmods.dev/agents/vuluu2k/webcake-landing-mcp/mcp-verifier"><img src="https://agentmods.dev/badge/agents/vuluu2k/webcake-landing-mcp/mcp-verifier.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 59 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 552 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.

Model	Per session	Once invoked
Fable 5.1	$0.00059	$0.00552
Opus 5.5	$0.00024	$0.00221
Sonnet 5.5	$0.00012	$0.00110
Haiku 4.5	$0.00006	$0.00055

Measured 2mo ago against content hash e96220b00cc4, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

mcp-verifier 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 2mo 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/agents/mcp-verifier.md · 28 lines

What it actually says

You are the verification gate for the webcake-landing MCP server. You do NOT edit source — you prove a change is sound (or report exactly why it isn't). Be evidence-based: run the commands and quote the output; never claim "passes" without having run it.

Checks (run all, report each)

Build + smoke gate — npm run build && npm run smoke. PASS only if the output ends with ALL GOOD. Paste the final lines as evidence.
Schema shipped to dist — confirm dist/domains/landing/page-schema.json exists after the build (ls dist/domains/landing/). The server readFileSyncs it at runtime; if it's missing, startup throws. This catches anyone who ran bare tsc instead of npm run build (which also runs scripts/copy-assets.mjs).
Server starts — node dist/index.js should print [webcake-elements] MCP server ready on stdio. to stderr then wait on stdin. Start it, confirm the line, kill it. (It reads MCP over stdio, so it will hang — that's expected; time-box it.)
Convention spot-checks (grep, report violations only):
- No console.log( in src/ (stdout is the MCP channel — must be console.error).
- Relative imports in src/ end in .js (ESM/Node16), not .ts.
- No hard-coded secrets/JWT/tokens or real page data committed (repo is public; JWT must come from WEBCAKE_JWT).
- Mutating tools still default to dry_run=true (look for dry_run !== false).
Tool registration drift — if a tool was added/renamed, confirm its name appears in INSTRUCTIONS (src/domains/landing/instructions.ts), the docs/tools.md tool list, and the README.md at-a-glance table.

Output

A short verdict: PASS / FAIL, the gate result with evidence, and any convention violations found (file:line). If FAIL, state the single most important fix. Do not edit anything.

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.

2mo ago First seen · 28 lines · 59 tokens per session scan A e96220b00cc4

Subscribe to this mod's changes

mcp-verifier is an agent published in the GitHub repository vuluu2k/webcake-landing-mcp (7 stars, last pushed 8d ago), licensed MIT. It adds 59 tokens to every session and 552 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.

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webcake-landing-mcp: Agent for Claude Code