Dry Run

ID	dry_run
Category	Safety
Tools	None
Features	None
Dependencies	None

Dry run lets you see what an agent would do before it does it. A session with this capability runs tools that only read, and answers every other tool call with a simulated result. Nothing is sent, written, or deleted.

The Test run button on an agent’s page starts a session with dry run on.

What runs for real

A tool runs for real when it declares itself read-only and nothing marks it destructive or requiring approval. MCP tools declare this through their own annotations or through a risk label set on the connection. Every tool that does not declare itself read-only is simulated: a dry run errs on the side of not acting.

What a simulated call returns

The call is recorded as a successful result with a dry_run object that names the tool and its arguments:

{
  "dry_run": {
    "simulated": true,
    "tool": "visti_send",
    "arguments": { "text": "main CI is red" },
    "note": "Dry run: `visti_send` was not executed. Nothing was changed."
  }
}

The agent is told it is in a dry run. It carries on as if simulated calls worked, so the rest of the run is exercised, and its final answer lists the actions it would have taken. The session trace marks simulated calls.

Configuration

Dry run has no settings. Add it to a session’s capabilities:

{ "capabilities": [{ "ref": "dry_run" }] }