Signal is on every plan, with a monthly issue limit per tier. At the limit it pauses until the next month. See pricing and usage.
Turn on Signal
Enabling Signal on a tracing project from the Signal tab.
Read your first issue
Signal groups recurring failures from your traces into ranked issues, each with an investigation and trace links.

Creating an evaluator directly from a Signal issue.
Configure Signal
Open ⋯ → Configure Signal to change the schedule or describe what your agent does and what counts as a failure, then click Save. On Enterprise plans you can also attach a GitHub repo, and Signal opens pull requests for its fixes. It never deploys them. See Signal for setup.Configuring Signal's schedule and context, including attaching a GitHub repo on Enterprise plans.