slash_command: scope option to restrict trigger event types

[neta-vega]

Problem

When using slash_command in an agentic workflow, the compiler generates triggers for all event types (issue_comment, issues, pull_request, pull_request_review_comment, discussion, discussion_comment). This means every PR open/edit event triggers the workflow, which immediately gets skipped at the pre_activation gate — but still shows up as a cancelled/skipped run in the Actions UI.

For workflows that are issue-only (e.g., a bug investigation pipeline where /investigate only makes sense on issues, not PRs), this creates significant noise. In our repo we have 4 agentic workflows in the bug pipeline, so every PR push creates 4 skipped runs.

Context

We have a label-based bug pipeline with 4 agentic workflows (investigator → analyst → fixer → PR review) dispatched via workflow_dispatch from a unified dispatcher. The /investigate, /analyze, /fix slash commands are only meant for manual re-triggers on issues. Every PR in the repo creates 4 extra skipped runs.

[neta-vega]

Update: Found that this is already supported via the events: field on slash_command:.

on:
  slash_command:
    name: investigate
    events: [issues, issue_comment]

This restricts the compiled triggers to only issues and issue_comment, removing pull_request, pull_request_review_comment, discussion, and discussion_comment from the generated .lock.yml. Documented at Command Triggers > Filtering Command Events.

Applied the fix to our three bug pipeline workflows and confirmed the compiled output no longer includes pull_request in the on: block.

Closing as not needed — the existing events: filter covers this use case. That said, it might be worth mentioning this in the slash_command section of the Triggers reference page (which currently just links to the command-triggers page without hinting that event filtering exists), since the default behavior of expanding to all events is a common source of noise.

[neta-vega]

Closing — already supported via events: field.

[pelikhan]

@copilot update slash commands docs