Low Risk

check_messages

Check messages addressed to you. Reads from comms/to-{your-agent-name}.json.

Part of the Agent Passport System — Cryptographic Identity for AI Agents MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.

AI agents call check_messages to retrieve information from Agent Passport System — Cryptographic Identity for AI Agents without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.

Even though check_messages only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.

Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.

agent-passport-system-cryptographic-identity-for-ai-agents.yaml
tools:
  check_messages:
    rules:
      - action: allow

See the full Agent Passport System — Cryptographic Identity for AI Agents policy for all 125 tools.

Tool Name check_messages
Category Read
Risk Level Low

View all 125 tools →

Agents calling read-class tools like check_messages have been implicated in these attack patterns. Read the full case and prevention policy for each:

Browse the full MCP Attack Database →

Other tools in the Read risk category across the catalogue. The same policy patterns (rate-limit, allow) apply to each.

What does the check_messages tool do? +

Check messages addressed to you. Reads from comms/to-{your-agent-name}.json.. It is categorised as a Read tool in the Agent Passport System — Cryptographic Identity for AI Agents MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on check_messages? +

Add a rule in your Intercept YAML policy under the tools section for check_messages. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the Agent Passport System — Cryptographic Identity for AI Agents MCP server.

What risk level is check_messages? +

check_messages is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit check_messages? +

Yes. Add a rate_limit block to the check_messages rule in your Intercept 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 check_messages completely? +

Set action: deny in the Intercept policy for check_messages. 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 check_messages? +

check_messages is provided by the Agent Passport System — Cryptographic Identity for AI Agents MCP server (agent-passport-system-mcp). Intercept sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policies on Agent Passport System — Cryptographic Identity for AI Agents

Open source. One binary. Zero dependencies.

npx -y @policylayer/intercept
github.com/policylayer/intercept →
// GET IN TOUCH

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