# tool_schema

Get the full schema for a specific tool including input validation rules

Agent View of the PolicyLayer registry record for `tool_schema`. HTML page: https://policylayer.com/tools/1mcp-app-agent/tool-schema

## Facts

- Tool: `tool_schema`
- Server: 1MCP Server (`1mcp-app/agent`) — https://policylayer.com/tools/1mcp-app-agent.md
- Homepage: https://github.com/1mcp-app/agent
- Risk category: Read (Low risk)
- Registry record: grade F, 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": "tool_schema",
    "arguments": {}
  }
}
```

## Why tool_schema is rated Low

This tool retrieves and returns metadata about tool schemas. It is a read-only query operation with no side effects, no code execution, no data modification, and no destructive operations. The blast radius of misuse is minimal—an agent could only learn about available tools' input structures, which is informational only. This clearly falls under the Read category.

From the tool's own definition: "Tool name 'tool_schema' and description 'Get the full schema for a specific tool' indicates a retrieval operation that queries schema information without modifying, executing, or deleting anything."

## Use case

AI agents call tool_schema to retrieve information from 1MCP Server 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 1MCP Server:

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

## Other tools on 1MCP Server (16)

- `mcp_uninstall` — Destructive — https://policylayer.com/tools/1mcp-app-agent/mcp-uninstall.md
- `mcp_install` — Execute — https://policylayer.com/tools/1mcp-app-agent/mcp-install.md
- `mcp_reload` — Execute — https://policylayer.com/tools/1mcp-app-agent/mcp-reload.md
- `tool_invoke` — Execute — https://policylayer.com/tools/1mcp-app-agent/tool-invoke.md
- `mcp_info` — Read — https://policylayer.com/tools/1mcp-app-agent/mcp-info.md
- `mcp_list` — Read — https://policylayer.com/tools/1mcp-app-agent/mcp-list.md
- `mcp_registry_info` — Read — https://policylayer.com/tools/1mcp-app-agent/mcp-registry-info.md
- `mcp_registry_list` — Read — https://policylayer.com/tools/1mcp-app-agent/mcp-registry-list.md
- `mcp_registry_status` — Read — https://policylayer.com/tools/1mcp-app-agent/mcp-registry-status.md
- `mcp_search` — Read — https://policylayer.com/tools/1mcp-app-agent/mcp-search.md
- `mcp_status` — Read — https://policylayer.com/tools/1mcp-app-agent/mcp-status.md
- `tool_list` — Read — https://policylayer.com/tools/1mcp-app-agent/tool-list.md
- `mcp_disable` — Write — https://policylayer.com/tools/1mcp-app-agent/mcp-disable.md
- `mcp_edit` — Write — https://policylayer.com/tools/1mcp-app-agent/mcp-edit.md
- `mcp_enable` — Write — https://policylayer.com/tools/1mcp-app-agent/mcp-enable.md
- `mcp_update` — Write — https://policylayer.com/tools/1mcp-app-agent/mcp-update.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=1mcp-app-agent · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/1mcp-app-agent