# inspect_tool_server

Live-inspect one active, provider-verified, operator-curated public MCP server from the 404.directory catalog. Returns only the remote read-only tools approved for gateway execution, including their current descriptions, JSON input schemas, and annotations. Use after search_tools and before the first invoke_registered_tool call, or whenever arguments may have changed. This operation does not execute a remote business tool.

Agent View of the PolicyLayer registry record for `inspect_tool_server`. HTML page: https://policylayer.com/tools/404-directory/inspect-tool-server

## Facts

- Tool: `inspect_tool_server`
- Server: 404 Directory (`MM-sheng/404-directory`) — https://policylayer.com/tools/404-directory.md
- Homepage: https://github.com/MM-sheng/404-directory
- Risk category: Read (Low risk)
- Registry record: grade D, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Allowed

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

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

## Why inspect_tool_server is rated Low

Tool retrieves metadata and schemas from curated servers without side effects or code execution.

From the tool's own definition: "Live-inspect active MCP server, returns read-only tools, descriptions, schemas, does not execute"

## Use case

AI agents call inspect_tool_server to retrieve information from 404 Directory without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches 404 Directory:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "inspect_tool_server": {}
  }
}
```

## Other tools on 404 Directory (10)

- `404_mcp` — Execute — https://policylayer.com/tools/404-directory/404-mcp.md
- `invoke_registered_tool` — Execute — https://policylayer.com/tools/404-directory/invoke-registered-tool.md
- `compare_tools` — Read — https://policylayer.com/tools/404-directory/compare-tools.md
- `get_capability_graph` — Read — https://policylayer.com/tools/404-directory/get-capability-graph.md
- `get_tool` — Read — https://policylayer.com/tools/404-directory/get-tool.md
- `get_trust_score` — Read — https://policylayer.com/tools/404-directory/get-trust-score.md
- `list_capabilities` — Read — https://policylayer.com/tools/404-directory/list-capabilities.md
- `recommend_tools` — Read — https://policylayer.com/tools/404-directory/recommend-tools.md
- `search_official_docs` — Read — https://policylayer.com/tools/404-directory/search-official-docs.md
- `search_tools` — Read — https://policylayer.com/tools/404-directory/search-tools.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=404-directory · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/404-directory