# crow_backend_schema

Show discovered tools and schema for a data backend.

Agent View of the PolicyLayer registry record for `crow_backend_schema`. HTML page: https://policylayer.com/tools/kh0pper-crow/crow-backend-schema

## Facts

- Tool: `crow_backend_schema`
- Server: Crow (`kh0pper/crow`) — https://policylayer.com/tools/kh0pper-crow.md
- Homepage: https://github.com/kh0pper/crow
- 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": "crow_backend_schema",
    "arguments": {}
  }
}
```

## Why crow_backend_schema is rated Low

This tool queries and returns schema metadata about a data backend's structure and available tools. The verb 'show' and the absence of any modification language (create, update, delete, execute) classify this as a Read operation. The severity is low because schema discovery poses minimal risk—it exposes structural information but not sensitive data itself, and has no side effects or operational impact.

From the tool's own definition: "Tool name 'crow_backend_schema' and description 'Show discovered tools and schema for a data backend' indicate a read-only operation that retrieves and displays schema information without modifying data."

## Use case

AI agents call crow_backend_schema to retrieve information from Crow 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 Crow:

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

## Other tools on Crow (586)

- `caddy_remove_site` — Destructive — https://policylayer.com/tools/kh0pper-crow/caddy-remove-site.md
- `crow_bookstack_delete` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-bookstack-delete.md
- `crow_campaign_delete` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-campaign-delete.md
- `crow_data_write` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-data-write.md
- `crow_deactivate_server` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-deactivate-server.md
- `crow_delete_bot_schedule` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-delete-bot-schedule.md
- `crow_delete_context_section` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-delete-context-section.md
- `crow_delete_file` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-delete-file.md
- `crow_delete_memory` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-delete-memory.md
- `crow_delete_post` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-delete-post.md
- `crow_delete_setlist` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-delete-setlist.md
- `crow_frigate_set_detect` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-frigate-set-detect.md
- `crow_glasses_undo_last_append` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-glasses-undo-last-append.md
- `crow_identity_revoke` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-identity-revoke.md
- `crow_kb_delete_article` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-kb-delete-article.md
- `crow_linkding_delete` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-linkding-delete.md
- `crow_media_playlist` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-media-playlist.md
- `crow_media_remove_source` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-media-remove-source.md
- `crow_miniflux_remove_feed` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-miniflux-remove-feed.md
- `crow_remove_backend` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-remove-backend.md
- `crow_remove_from_setlist` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-remove-from-setlist.md
- `crow_revoke_access` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-revoke-access.md
- `crow_revoke_instance` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-revoke-instance.md
- `crow_shiori_delete` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-shiori-delete.md
- `crow_tax_purge_return` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-tax-purge-return.md
- `crow_trilium_delete_note` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-trilium-delete-note.md
- `crow_vikunja_delete_task` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-vikunja-delete-task.md
- `crow_wallabag_delete` — Destructive — https://policylayer.com/tools/kh0pper-crow/crow-wallabag-delete.md
- `crowdsec_delete_decision` — Destructive — https://policylayer.com/tools/kh0pper-crow/crowdsec-delete-decision.md
- `fw_defederate` — Destructive — https://policylayer.com/tools/kh0pper-crow/fw-defederate.md
- …and 556 more: https://policylayer.com/tools/kh0pper-crow.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=kh0pper-crow · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/kh0pper-crow