# mastodon_block_domain

Block a remote domain at the user level (hide all accounts from that domain for the authenticated user). For instance-wide defederation use mastodon_defederate. Rate-limited: 5/hour.

Agent View of the PolicyLayer registry record for `mastodon_block_domain`. HTML page: https://policylayer.com/tools/kh0pper-crow/mastodon-block-domain

## Facts

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

## Why mastodon_block_domain is rated Medium

This tool creates a user-level domain block, which modifies the authenticated user's account settings by hiding all accounts from the specified domain. It is reversible (blocks can be undone), so it falls under Write rather than Destructive. Misuse could silently cut off large portions of the fediverse for a user, giving it medium severity.

From the tool's own definition: "Block a remote domain at the user level (hide all accounts from that domain for the authenticated user)"

## Use case

AI agents use mastodon_block_domain to create or update resources in Crow, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Crow environment.

## Recommended policy (PolicyLayer)

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

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "mastodon_block_domain": {
      "limits": [
        {
          "counter": "mastodon_block_domain_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## 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`

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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