# subtract

A other tool on the Mcp Test Servers MCP server.

Agent View of the PolicyLayer registry record for `subtract`. HTML page: https://policylayer.com/tools/mcp-test-servers/subtract

## Facts

- Tool: `subtract`
- Server: Mcp Test Servers (`msfeldstein/mcp-test-servers`) — https://policylayer.com/tools/mcp-test-servers.md
- Homepage: https://github.com/msfeldstein/mcp-test-servers
- Risk category: Other (Low risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Rate-limited

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "subtract",
    "arguments": {}
  }
}
```

## Why subtract is rated Low

The name 'subtract' most likely refers to a basic arithmetic operation (similar to the sibling tool 'add'), which would be a pure computation with no side effects. However, with no description to confirm this, confidence is low. Arithmetic tools are generally harmless and fall outside the primary risk categories.

From the tool's own definition: "Tool name is 'subtract'; description is empty and uninformative."

## Use case

AI agents call subtract as a supporting operation in Mcp Test Servers workflows.

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Mcp Test Servers:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "subtract": {
      "limits": [
        {
          "counter": "subtract_rate",
          "window": "minute",
          "max": 60,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Mcp Test Servers (66)

- `delete-project` — Destructive — https://policylayer.com/tools/mcp-test-servers/delete-project.md
- `execute-sql` — Execute — https://policylayer.com/tools/mcp-test-servers/execute-sql.md
- `long-running-task` — Execute — https://policylayer.com/tools/mcp-test-servers/long-running-task.md
- `long-running-task-with-message` — Execute — https://policylayer.com/tools/mcp-test-servers/long-running-task-with-message.md
- `long-running-task-with-no-total` — Execute — https://policylayer.com/tools/mcp-test-servers/long-running-task-with-no-total.md
- `ping` — Execute — https://policylayer.com/tools/mcp-test-servers/ping.md
- `start-notification-stream` — Execute — https://policylayer.com/tools/mcp-test-servers/start-notification-stream.md
- `toggle_dynamic_tool` — Execute — https://policylayer.com/tools/mcp-test-servers/toggle-dynamic-tool.md
- `add` — Other — https://policylayer.com/tools/mcp-test-servers/add.md
- `all_types_tool` — Other — https://policylayer.com/tools/mcp-test-servers/all-types-tool.md
- `another-missing-type` — Other — https://policylayer.com/tools/mcp-test-servers/another-missing-type.md
- `bad-param` — Other — https://policylayer.com/tools/mcp-test-servers/bad-param.md
- `crash` — Other — https://policylayer.com/tools/mcp-test-servers/crash.md
- `divide` — Other — https://policylayer.com/tools/mcp-test-servers/divide.md
- `dynamic_feature` — Other — https://policylayer.com/tools/mcp-test-servers/dynamic-feature.md
- `echo` — Other — https://policylayer.com/tools/mcp-test-servers/echo.md
- `echo_structured` — Other — https://policylayer.com/tools/mcp-test-servers/echo-structured.md
- `echo_with_params` — Other — https://policylayer.com/tools/mcp-test-servers/echo-with-params.md
- `env_echo` — Other — https://policylayer.com/tools/mcp-test-servers/env-echo.md
- `fizzbuzz` — Other — https://policylayer.com/tools/mcp-test-servers/fizzbuzz.md
- `format_data` — Other — https://policylayer.com/tools/mcp-test-servers/format-data.md
- `generate_big_response` — Other — https://policylayer.com/tools/mcp-test-servers/generate-big-response.md
- `long_running_progress` — Other — https://policylayer.com/tools/mcp-test-servers/long-running-progress.md
- `many-resources-tool` — Other — https://policylayer.com/tools/mcp-test-servers/many-resources-tool.md
- `missing-type-tool` — Other — https://policylayer.com/tools/mcp-test-servers/missing-type-tool.md
- `multiply` — Other — https://policylayer.com/tools/mcp-test-servers/multiply.md
- `number-param` — Other — https://policylayer.com/tools/mcp-test-servers/number-param.md
- `optionalTool` — Other — https://policylayer.com/tools/mcp-test-servers/optionaltool.md
- `power` — Other — https://policylayer.com/tools/mcp-test-servers/power.md
- `root-echo` — Other — https://policylayer.com/tools/mcp-test-servers/root-echo.md
- …and 36 more: https://policylayer.com/tools/mcp-test-servers.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=mcp-test-servers · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/mcp-test-servers