watchers.crypto-address-activity · MCP: Risk & Policy

WHAT IT DOES

What watchers.crypto-address-activity does on Mcp

AI agents invoke watchers.crypto-address-activity to trigger actions in Mcp. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why watchers.crypto-address-activity needs a policy

This tool sets up an active watcher that triggers external HTTP callbacks (POSTing to a callbackUrl) when blockchain activity occurs. It executes an ongoing external operation — arming a monitoring service that will fire outbound network requests.

From the tool's definition 'get a signed callback the moment a crypto address transacts', 'Arm once, pay once', 'POST your custom payload to callbackUrl when the address sends/receives'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

watchers.crypto-address-activity Rate-limited

watchers.crypto-address-activity stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "watchers.crypto-address-activity": {
      "limits": [
        {
          "counter": "watchers.crypto-address-activity_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Mcp, so you can run agents against it safely.

FAQ

Questions about watchers.crypto-address-activity

What does the watchers.crypto-address-activity tool do? +

WATCHER: get a signed callback the moment a crypto address transacts. Arm once, pay once (no account, no API key) — we watch Base, Ethereum, or Bitcoin and POST your custom payload to callbackUrl when the address sends/receives native coins, ERC-20s, or ERC-721s. Filter by direction (in/out/both), asset type, and a USD. It is categorised as a Execute tool in the Mcp MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on watchers.crypto-address-activity? +

Register the MCP server in PolicyLayer and add a rule for watchers.crypto-address-activity: 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 Mcp. Nothing to install.

What risk level is watchers.crypto-address-activity? +

watchers.crypto-address-activity is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit watchers.crypto-address-activity? +

Yes. Add a rate_limit block to the watchers.crypto-address-activity 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.

How do I block watchers.crypto-address-activity completely? +

Set action: deny in the PolicyLayer policy for watchers.crypto-address-activity. 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.

What MCP server provides watchers.crypto-address-activity? +

watchers.crypto-address-activity is provided by the MCP server (@2sio/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.