ows_sign_message · Execution Market MCP: Risk & Policy

WHAT IT DOES

What ows_sign_message does on Execution Market

AI agents invoke ows_sign_message to trigger actions in Execution Market. 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 ows_sign_message needs a policy

Signing a message with a wallet is an execution action that produces a cryptographic signature. In the context of a financial marketplace using USDC payments and escrow, a signed message can authorize transactions, approve payouts, or commit to financial obligations on-chain. While signing alone doesn't move funds, it produces an artifact that can trigger irreversible financial operations, making it high severity.

From the tool's definition 'Sign a message using a wallet. Supports EVM, Solana, and other chains.'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

ows_sign_message Rate-limited

ows_sign_message 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": {
    "ows_sign_message": {
      "limits": [
        {
          "counter": "ows_sign_message_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 Execution Market, so you can run agents against it safely.

FAQ

Questions about ows_sign_message

What does the ows_sign_message tool do? +

Sign a message using a wallet. Supports EVM, Solana, and other chains. It is categorised as a Execute tool in the Execution Market MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on ows_sign_message? +

Register the Execution Market MCP server in PolicyLayer and add a rule for ows_sign_message: 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 Execution Market. Nothing to install.

What risk level is ows_sign_message? +

ows_sign_message is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit ows_sign_message? +

Yes. Add a rate_limit block to the ows_sign_message 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 ows_sign_message completely? +

Set action: deny in the PolicyLayer policy for ows_sign_message. 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 ows_sign_message? +

ows_sign_message is provided by the Execution Market MCP server (https://mcp.execution.market/mcp/). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.