Import a domain blocklist (IFTAS / Bad Space / custom URL). QUEUED — requires operator confirmation. Rate-limited: 2/hour.
AI agents use mastodon_import_blocklist 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.
The tool writes/modifies blocklist data by importing domain lists into a Mastodon instance. While import operations are generally reversible (existing blocklists can be removed or replaced), the effects are significant: incorrect blocklist imports could block legitimate domains or fail to block malicious ones, impacting instance-wide federation and user access.
From the tool's definition Tool performs an import action that modifies blocking configuration ("Import a domain blocklist"). The description indicates it creates or modifies blocklist data on the Mastodon instance, which is a reversible change that can be updated or reverted.
Documented attack patterns abuse exactly the kind of access mastodon_import_blocklist gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Crow, and nothing reaches the server without passing your rules. This is the rule we recommend for mastodon_import_blocklist:
{
"version": "1",
"default": "deny",
"tools": {
"mastodon_import_blocklist": {
"limits": [
{
"counter": "mastodon_import_blocklist_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}mastodon_import_blocklist stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Import a domain blocklist (IFTAS / Bad Space / custom URL). QUEUED — requires operator confirmation. Rate-limited: 2/hour. It is categorised as a Write tool in the Crow MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Crow MCP server in PolicyLayer and add a rule for mastodon_import_blocklist: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Crow. Nothing to install.
mastodon_import_blocklist is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the mastodon_import_blocklist rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for mastodon_import_blocklist. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
mastodon_import_blocklist is provided by the Crow MCP server (kh0pper/crow). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Crow, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
576 Crow tools catalogued and risk-classified — across an index of 43,000+ MCP servers.