# list_categories

Return every Agent Papers category with counts and short descriptions so an agent can choose the right comparison surface.

Agent View of the PolicyLayer registry record for `list_categories`. HTML page: https://policylayer.com/tools/dev-agentpapers-agent-papers/list-categories

## Facts

- Tool: `list_categories`
- Server: Agent Papers (`https://agentpapers.dev/api/mcp`) — https://policylayer.com/tools/dev-agentpapers-agent-papers.md
- Homepage: https://github.com/https://agentpapers.dev/api/mcp
- Risk category: Read (Low risk)
- Registry record: grade D, identity unverified
- Server auth posture: open
- Server CORS policy: *
- 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": "list_categories",
    "arguments": {}
  }
}
```

## Why list_categories is rated Low

list_categories is a read-only operation that retrieves metadata about available categories. It has no side effects, does not modify data, and does not execute code or trigger external actions. The blast radius is minimal—an agent can only discover what categories exist and their descriptions, which is non-sensitive structural information.

From the tool's own definition: "Tool returns category listings with counts and descriptions; purely informational with no modification, deletion, or execution of external operations."

Risk signals: Bulk/mass operation — affects multiple targets

## Use case

AI agents call list_categories to retrieve information from Agent Papers 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 Agent Papers:

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

## Other tools on Agent Papers (5)

- `compare` — Read — https://policylayer.com/tools/dev-agentpapers-agent-papers/compare.md
- `get_company` — Read — https://policylayer.com/tools/dev-agentpapers-agent-papers/get-company.md
- `get_schema` — Read — https://policylayer.com/tools/dev-agentpapers-agent-papers/get-schema.md
- `search` — Read — https://policylayer.com/tools/dev-agentpapers-agent-papers/search.md
- `whats_new` — Read — https://policylayer.com/tools/dev-agentpapers-agent-papers/whats-new.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=dev-agentpapers-agent-papers · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/dev-agentpapers-agent-papers