# Tool Guardian (pypi · tool-guardian)

MCP router that keeps tool definitions out of the context window and finds tools on demand.

- Trust score: 74/100 (medium)
- Change this week: −9
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-04

## Components

- pypi · `tool-guardian`: 74/100 (this document), [markdown](https://verifymcp.io/servers/luminarisoftwares-tool-guardian/tool-guardian.md), [page](https://verifymcp.io/servers/luminarisoftwares-tool-guardian/tool-guardian)

## Channel facts

- Registry: `pypi`
- Package: `tool-guardian`
- Version: `0.9.1`
- Transport: `stdio`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-11-04.

- **Supply Chain Security**: 50/100
  - Malware scan not yet available for this package.
  - No known CVEs affecting this package version or its production dependencies.
  - Runs setuptools.build_meta at install time, a recognised build step with no custom scripting around it.
  - No production dependencies, so there is no dependency health to assess.
- **Provenance & Transparency**: 100/100
  - Source repository is publicly reachable at the declared URL.
  - Cryptographically verified build provenance (signed, bound to LuminariSoftwares/tool-guardian).
  - Clear OSI-approved license (MIT).
  - Actively maintained (last published 3 days ago).
  - Publishes a security disclosure policy (SECURITY.md).
- **Schema Quality & AI Usability**: 72/100
  - AI-judged instruction clarity (good).
  - Tool/resource definitions use about 476 tokens (~79/item across 6 items; 6 tools + 0 resources), lean.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 67/100
  - Stability observed for 20 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 88/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 64% of tool parameters carry a description.
- **Tool Safety**: 100/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - We read all 6 captured tool definition(s), and no name or description among them implies an irreversible operation.
  - An AI judge read all 6 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.

## Install

### How do I install the Tool Guardian MCP server?

Tool Guardian runs locally as a PyPI package, launched with uvx tool-guardian. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add luminarisoftwares-tool-guardian -- uvx tool-guardian
```

### Cursor

```json
{
  "mcpServers": {
    "luminarisoftwares-tool-guardian": {
      "command": "uvx",
      "args": [
        "tool-guardian"
      ]
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "luminarisoftwares-tool-guardian": {
      "command": "uvx",
      "args": [
        "tool-guardian"
      ]
    }
  }
}
```

### Codex

```bash
codex mcp add luminarisoftwares-tool-guardian -- uvx tool-guardian
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "luminarisoftwares-tool-guardian": {
      "type": "local",
      "command": [
        "uvx",
        "tool-guardian"
      ],
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add luminarisoftwares-tool-guardian --command uvx --arg tool-guardian
```

### Hermes

```yaml
mcp_servers:
  luminarisoftwares-tool-guardian:
    command: "uvx"
    args: ["tool-guardian"]
```

### Netclaw

```json
{
  "McpServers": {
    "luminarisoftwares-tool-guardian": {
      "Transport": "stdio",
      "Command": "uvx",
      "Arguments": [
        "tool-guardian"
      ]
    }
  }
}
```

### Vellum

```bash
assistant mcp add luminarisoftwares-tool-guardian -t stdio -c uvx -a tool-guardian
```

### Other

```json
{
  "mcpServers": {
    "luminarisoftwares-tool-guardian": {
      "command": "uvx",
      "args": [
        "tool-guardian"
      ]
    }
  }
}
```

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-11-04 (score 74, −15)

- [security regression] Malware scan: pass → unverified

### 2026-11-03 (score 89, +1)

No change was recorded against any check on this day. Stability & Change Management went from 60 to 63. That category is still filling its 30-day observation window: 18 days of observed history at the previous scan, 19 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-11-01 (score 88, +19)

- [security regression] Stability: 0.53 → unverified
- [security regression] Tool safety: pass → unverified
- [security improvement] Malware scan: unverified → pass
- [functional regression] Capabilities: fail → unverified
- [functional regression] Tool coverage: 100 → unverified
- [functional improvement] MCP protocol: fail → pass
- [functional] First check of Schema quality: unverified
- [functional] Package version: 0.8.1 → 0.9.1

### 2026-10-31 (score 69, −15)

- [security regression] Malware scan: pass → unverified

### 2026-10-30 (score 84, +16)

- [security improvement] Malware scan: unverified → pass

### 2026-10-29 (score 68, −15)

- [security regression] Malware scan: pass → unverified

### 2026-10-28 (score 83, +16)

- [security improvement] Malware scan: unverified → pass

### 2026-10-27 (score 67, −15)

- [security regression] Malware scan: pass → unverified

## MCP tools (6)

### `list_capabilities` (~67 tokens)

List server tools

List the tools on the connected MCP servers. No server is reachable yet; this says why. With a keyword, search_capabilities is cheaper. Read-only. Returns a line per tool, else per server with any error.

Input parameters:

- `server` (string): Catalogue name; omit for all.

### `describe_tool` (~70 tokens)

Describe a tool

Get the arguments of ONE backend tool, before call_tool. `server`/`tool` are catalogue names; an unknown one returns the valid ones. Read-only. Returns each argument and its type.

Input parameters:

- `detail` (string)
- `server` (string, required)
- `tool` (string, required)

### `call_tool` (~94 tokens)

Call a backend tool

Invoke a tool on a connected server. THIS IS THE STEP THAT ANSWERS THE USER -- list_capabilities only finds the name. `server`/`tool` are catalogue names. Side effects are the backend tool's own. Returns its result as text, big ones via retrieve_spill.

Input parameters:

- `args`: Object or JSON string; omit if none.
- `server` (string, required)
- `tool` (string, required)

### `search_capabilities` (~89 tokens)

Search tools

Find a tool by keyword on every connected server; cheaper than list_capabilities when you know roughly what you want. Read-only. Returns a line per match, best first, with args.

Input parameters:

- `limit` (integer): Max matches, 1-25 (clamped).
- `query` (string, required): Words matched on tool names.
- `server` (string): One server; omit for all.

### `list_groups_with_costs` (~44 tokens)

List tool groups and costs

Tool GROUPS with the context-token cost of loading each; to find a tool use list_capabilities. Read-only. Returns a line per group and the totals.

### `retrieve_spill` (~112 tokens)

Read an archived result

Read back the FULL original of a result call_tool shortened, by the id in its notice; an unknown or pruned id fails saying so. Read-only. Returns a text window, or grep's lines.

Input parameters:

- `grep` (string): Regex; omit for a window.
- `id` (string, required): sp_ + 12 hex, from the notice.
- `max_lines` (integer): Max lines/matches, 1-2000.
- `start_line` (integer): The window's first line.

## Diagnostics

Captured diagnostic sections: Provenance, Install scripts, Dependencies. The full working is on the page: https://verifymcp.io/servers/luminarisoftwares-tool-guardian/tool-guardian#diagnostics

## Score history

- 2026-11-04: 74
- 2026-11-03: 89
- 2026-11-02: 88
- 2026-11-01: 88
- 2026-10-31: 69
- 2026-10-30: 84
- 2026-10-29: 68
- 2026-10-28: 83
- 2026-10-27: 67
- 2026-10-26: 82
- 2026-10-25: 66
- 2026-10-24: 66
- 2026-10-23: 55
- 2026-10-22: 55
- 2026-10-21: 49
- 2026-10-20: 49
- 2026-10-19: 49
- 2026-10-18: 49
- 2026-10-17: 64
- 2026-10-16: 49
- 2026-10-15: 64

## Common questions

### What is the Tool Guardian MCP server?

Tool Guardian is an MCP server listed in the public MCP registry as io.github.LuminariSoftwares/tool-guardian. MCP router that keeps tool definitions out of the context window and finds tools on demand. This page covers its PyPI package (tool-guardian).

### Is the Tool Guardian MCP server safe to use?

Tool Guardian scores 74 out of 100 on VerifyMCP. We found no known CVEs affecting it as of 4 November 2026. Its build provenance is signed and verified. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the Tool Guardian MCP server expose?

Tool Guardian exposes 6 tools: list_capabilities, describe_tool, call_tool, search_capabilities, list_groups_with_costs, retrieve_spill. Their descriptions and schemas cost roughly 476 tokens of context every time the server is loaded.

### Is the Tool Guardian MCP server still maintained?

Tool Guardian is still listed as active in the MCP registry. We last reached this channel on 4 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

### What licence is the Tool Guardian MCP server under?

Tool Guardian declares the MIT licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.

## Links

- PyPI project: https://pypi.org/project/tool-guardian/
- Socket report: https://socket.dev/pypi/package/tool-guardian
- Repository: https://github.com/LuminariSoftwares/tool-guardian
- Changelog RSS feed: https://verifymcp.io/servers/luminarisoftwares-tool-guardian/tool-guardian.xml
- Changelog JSON feed: https://verifymcp.io/servers/luminarisoftwares-tool-guardian/tool-guardian.json
- HTML version of this page: https://verifymcp.io/servers/luminarisoftwares-tool-guardian/tool-guardian