Medium Risk

message-task

Send a follow-up message to an existing task on its original session. Use this to steer a running task, refine completed work, or add instructions after reviewing partial results. After calling, follow up with `wait-task` exactly like after `spawn-task`.

Part of the Mcp Codex Worker MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.

mcp-codex-worker Write Risk 2/5

AI agents use message-task to create or modify resources in Mcp Codex Worker. Write operations carry medium risk because an autonomous agent could trigger bulk unintended modifications. Rate limits prevent a single agent session from making hundreds of changes in rapid succession. Argument validation ensures the agent passes expected values.

Without a policy, an AI agent could call message-task repeatedly, creating or modifying resources faster than any human could review. Intercept's rate limiting ensures write operations happen at a controlled pace, and argument validation catches malformed or unexpected inputs before they reach Mcp Codex Worker.

Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.

mcp-codex-worker.yaml
tools:
  message-task:
    rules:
      - action: allow
        rate_limit:
          max: 30
          window: 60

See the full Mcp Codex Worker policy for all 5 tools.

Tool Name message-task
Category Write
Risk Level Medium

Agents calling write-class tools like message-task 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 Write risk category across the catalogue. The same policy patterns (rate-limit, validate) apply to each.

What does the message-task tool do? +

Send a follow-up message to an existing task on its original session. Use this to steer a running task, refine completed work, or add instructions after reviewing partial results. After calling, follow up with `wait-task` exactly like after `spawn-task`.. It is categorised as a Write tool in the Mcp Codex Worker MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on message-task? +

Add a rule in your Intercept YAML policy under the tools section for message-task. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the Mcp Codex Worker MCP server.

What risk level is message-task? +

message-task is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit message-task? +

Yes. Add a rate_limit block to the message-task 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 message-task completely? +

Set action: deny in the Intercept policy for message-task. 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 message-task? +

message-task is provided by the Mcp Codex Worker MCP server (mcp-codex-worker). Intercept sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policies on Mcp Codex Worker

Open source. One binary. Zero dependencies.

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

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