Add a new URL to watch. Change Detection will begin polling it on its default schedule.
AI agents use changedetection_create_watch 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.
This tool creates a new watch entry in the system, which is a reversible Write operation. While it initiates monitoring of a URL, the actual effect is creating/storing a new configuration record. The severity is medium because misuse could lead to resource consumption through monitoring untrusted URLs, but the action itself is not destructive, financial, or irreversible in a data-loss sense.
From the tool's definition Tool description: 'Add a new URL to watch. Change Detection will begin polling it on its default schedule.' The verb 'Add' and the action of creating a new watch entry indicates data creation.
Documented attack patterns abuse exactly the kind of access changedetection_create_watch 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 changedetection_create_watch:
{
"version": "1",
"default": "deny",
"tools": {
"changedetection_create_watch": {
"limits": [
{
"counter": "changedetection_create_watch_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}changedetection_create_watch 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.
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Add a new URL to watch. Change Detection will begin polling it on its default schedule. 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 changedetection_create_watch: 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.
changedetection_create_watch 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 changedetection_create_watch 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 changedetection_create_watch. 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.
changedetection_create_watch 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.
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576 Crow tools catalogued and risk-classified — across an index of 43,000+ MCP servers.