docs: clarify how workflow triggers and prompts interact

workflows/index.mdx

@@ -20,10 +20,18 @@
 
 Workflows support two trigger types.
 
 - **Schedule (cron)** — Run on a recurring daily, weekly, or monthly schedule. Workflows queue within 10 minutes of the scheduled time.
 - **Push events** — Run when changes push to a specific repository or branch, including pull request merges and direct pushes.
 
-You cannot combine trigger types in a single workflow. Each workflow has exactly one trigger. 
+You cannot combine trigger types in a single workflow. Each workflow has exactly one trigger.
+
+### How triggers and prompts work together
+
+Triggers control _how often_ a workflow runs. The prompt controls _what the agent does_ once it is running.
+
+- Triggers fire on every qualifying event. Push triggers run on every push to the configured branch, regardless of which files changed. Schedule triggers run on every scheduled occurrence. There is no built-in path filter or pre-flight check that decides whether to skip a run.
+- The prompt is where conditional logic belongs. Write instructions that tell the agent to evaluate whether a change is warranted and to take no action if it is not. For example: "Review changes in the linked repository since the last run. If no user-facing behavior changed, do not open a pull request."
+- To reduce run frequency, switch to a schedule trigger (daily or weekly) instead of relying on every push. Failed runs do not count against [usage limits](#usage-limits).
 
 ## Usage limits