Skills/PyPI/mcp2mcpb

mcp2mcpb@1.0.0

CAUTION· not started

Publisher claims: "Convert PyPI/npm MCP servers into one-click .mcpb bundles for Claude Desktop" Observed in sandbox: no network, touches nothing outside the project, writes no memory.

Registry PyPI (MCP server)Publisher anselmoo · publishing for 472 daysInstalls 46Last detonated 4d ago

Coverage

Not started: dependency install failed; the server itself was not observed.
Tested
the dependency install step · every file read, file written and host contacted by what ran
Not tested
server startup · the tool list · tool behavior

What this means for the label: Caution here covers what ran. The server's tools were not exercised with a real credential, so nothing about their behavior is asserted; the credential summary below says what to do with that.

Before you give it your token

It will ask for
no credential variables read in the code
Where it talks to
no vendor host named in the code
What the honeypot saw
no credential files read · no network
What we could not test
server startup · the tool list · tool behavior

Connect it under the guard. Not started: dependency install failed; the server itself was not observed. The code names no credential variable; the guard pins the network to what the honeypot saw and logs every call.

$vet-skills run --net declared -- uvx mcp2mcpb

Never paste a credential into a chat, a ticket or a report, including ours. How the guard holds it.

Is [email protected] safe to install?

KillerSkills ran it in the KillerSkills honeypot sandbox (2 scenarios; not started: dependency install failed; the server itself was not observed) on 2026-11-10 and scored it 73/100 (Caution). It is not known to be malicious, but it has behaviour or code a security policy should decide on before install. Notable findings: Collapsed <details> block carrying instructions; Collapsed <details> block carrying instructions; Collapsed <details> block carrying instructions. Summary: no network, touches nothing outside the project, writes no memory.

Behavior trace

Honeypot run · 0 s · 2 scenarios · 0 deviations
t+CategoryObserved action
0.0sprocessno install scripts in bundle
0.1sprocessdependency install exit 1 ·
0.1sclaimednot started: dependency install failed (exit 1); the server itself was not observed
0.1sprocessscript backend runs setup only
0.1sprocessno install scripts to re-run

Static findings

HIGH
Collapsed <details> block carrying instructionsREADME.md:331 · Collapsed <details> block carrying instructions<summary><b>fetch</b> — an official PyPI server, no overrides (<code>mcp-server-fetch</code>)</summary> <br> The reference [fetch](https://github.com/modelconteFix: Remove the text that addresses the agent rather than the reader; describe behavior, do not instruct.
AST01
MEDIUM
npx invocation of non-well-known package.github/workflows/build-mcpb.yml:59 · npx invocation of non-well-known package — may execute untrusted codedescription: "Launch runner: uvx | npx | uv-run | python | node (empty = infer)."Fix: Pin versions and sources; vendor anything fetched at install time.
AST06
MEDIUM
npx invocation of non-well-known packagesrc/mcp2mcpb/models.py:46 · npx invocation of non-well-known package — may execute untrusted codeNPX = "npx"Fix: Pin versions and sources; vendor anything fetched at install time.
AST06
HIGH
Collapsed <details> block carrying instructionsREADME.md:275 · Collapsed <details> block carrying instructions<summary><b>serena</b> — a PyPI server behind a subcommand (<code>serena-agent</code>)</summary> <br> [Serena](https://github.com/oraios/serena) exposes its MCPFix: Remove the text that addresses the agent rather than the reader; describe behavior, do not instruct.
AST01
MEDIUM
npx invocation of non-well-known packagetests/test_models.py:116 · npx invocation of non-well-known package — may execute untrusted codespec.runner = Runner.NPX # frozenFix: Pin versions and sources; vendor anything fetched at install time.
AST06
MEDIUM
npx invocation of non-well-known packageaction.yml:31 · npx invocation of non-well-known package — may execute untrusted codeproduces a lightweight manifest that calls uvx or npx at runtime.Fix: Pin versions and sources; vendor anything fetched at install time.
AST06
MEDIUM
Python subprocess execution detectedtests/test_ci_args.py:147 · Python subprocess execution detectedproc = subprocess.run(Fix: Build commands from fixed arguments, never from interpolated strings; prefer an API client over shelling out.
AST05
MEDIUM
Python subprocess execution detectedtests/test_ci_args.py:133 · Python subprocess execution detectedproc = subprocess.run(Fix: Build commands from fixed arguments, never from interpolated strings; prefer an API client over shelling out.
AST05
HIGH
Collapsed <details> block carrying instructionsREADME.md:355 · Collapsed <details> block carrying instructions<summary><b>serena via <code>.mcpb.toml</code></b> — keep the recipe in a config file</summary> <br> Drop a `.mcpb.toml` in the directory you run the converter Fix: Remove the text that addresses the agent rather than the reader; describe behavior, do not instruct.
AST01
MEDIUM
npx invocation of non-well-known packagetests/test_launch.py:25 · npx invocation of non-well-known package — may execute untrusted codeassert default_launch(Registry.NPM, BundleMode.REFERENCE).runner is Runner.NPXFix: Pin versions and sources; vendor anything fetched at install time.
AST06
MEDIUM
File type combined with upload actiontests/test_cli_more.py:307 · File type combined with upload action — agent may exfiltrate local data filesassert "Auto-detected manifest.json" in result.outputFix: Remove the call, or declare the host in frontmatter and explain in the README what is sent and why.
AST07
MEDIUM
npx invocation of non-well-known packagetests/test_launch.py:74 · npx invocation of non-well-known package — may execute untrusted codeassert ov.runner is Runner.NPXFix: Pin versions and sources; vendor anything fetched at install time.
AST06
MEDIUM
File type combined with upload actiontests/test_cli_more.py:194 · File type combined with upload action — agent may exfiltrate local data filesassert "no manifest.json" in result.outputFix: Remove the call, or declare the host in frontmatter and explain in the README what is sent and why.
AST07
MEDIUM
npx invocation of non-well-known packagesrc/mcp2mcpb/bundler.py:3 · npx invocation of non-well-known package — may execute untrusted codeIn ``reference`` mode this is a no-op — the manifest calls uvx/npx atFix: Pin versions and sources; vendor anything fetched at install time.
AST06

Cost to the agent

Instructions loaded
≈911 tok
2 files · 65 in bundle
Tool list per prompt
≈0 tok
0 tools · 0 per tool
Handshake
no reply
launch to tools/list, stdio
Undocumented tools
0
description under 20 chars · avg 0

Tokens estimated at four characters each. The tool list is re-read by the agent on every turn, so it is the number to compare between servers that do the same job: ranked across the index.

Known vulnerabilities

No advisories in OSV for mcp2mcpb@1.0.0 as of 4d ago. This is the package itself, not its dependencies.

What would make this Verified

7 points to 80 · weights: behavior 45%, static 25%, prompt 15%, publisher 15%
  1. Text that tells the agent to ignore its instructions≈ +9 on the totalDelete phrases like "ignore previous instructions", "override", "bypass" from SKILL.md and tool descriptions. Describe what the skill does; do not instruct the agent about other rules.
  2. Unclaimed publisher≈ +8 on the totalClaim anselmoo: a verified publisher gets +50 on publisher trust. It is free and usually instant with GitHub sign-in.
  3. Hidden instructions≈ +6 on the totalRemove HTML comments, zero-width characters and white-on-white text that carry instructions. Everything the agent is meant to read should be visible to the person reading the file.
  4. npx invocation of non-well-known package≈ +2 on the totalPin versions and sources; vendor anything fetched at install time.
  5. Python subprocess execution detected≈ +2 on the totalBuild commands from fixed arguments, never from interpolated strings; prefer an API client over shelling out.
  6. File type combined with upload action≈ +2 on the totalRemove the call, or declare the host in frontmatter and explain in the README what is sent and why.
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