Monitor tool reworks its output handling, rate limiting and description

What

The Monitor tool lets Claude run a script in the background and get notified as the script prints output. Several parts of it changed in this release:

• Stderr guidance in the tool's prompt now depends on a runtime check. Stderr is the error output a script prints. In one case the prompt says stderr does not trigger notifications and that only its last few lines appear in the notice sent when the script ends. In the other case it says stderr goes to the output file. Before, the prompt always said stderr went to the output file, readable with Read, without triggering notifications.
• The tool gains an inputJSONSchema getter, which supplies the description of the inputs the tool accepts.
• Under a certain runtime condition, part of the tool's description is left out.
• The rate limiter, which stops a very noisy script from flooding the conversation, now takes a configurable bucket with a capacity and a refillMs setting instead of a fixed one. It also exposes onBatch and dropAndClose, so output can be handed over in batches and the limiter can be shut down.
• The message shown when events are suppressed is now built by a shared helper. It used to be written inline as "events suppressed — output rate too high. Consider using TaskStop to restart this monitor with a more selective filter."

Why

If you use Monitor to watch logs or long-running scripts, error output may now show up differently. Depending on the condition, you may only see the last lines of stderr once the script finishes, not in the output file. Fast-printing scripts may also have their output grouped into batches or limited by different rules than before.