Repeating from the chat conversation:

This happens for all subpages (details, errors, shortcuts). The toolbar search is considered global and does the same thing regardless of context (forwards the user to a filtered list of apps/extensions). User can still search with ctrl+f for in-page content.

Alternatives:
1) Hide toolbar search when not in main page.
2) Change behavior of toolbar search depending on page.

Regarding 1: It might make the toolbar look odd without a search field.
Regarding 2, IMO is overly complex for the task at hand. Ctrl+F still works, and taking this approach would not add much value (given that a super long list of shortcuts is not common).

Current approach's advantage is simplicity, both in implementation and from user's perspective. I acknowledge that this might be jarring the first time a user searches from the Shortcuts page, but this is why the placeholder text says "Search Extensions" and not "Search shortcuts".

Closing this as WAI, after consulting with @bettes.