This plugin shows "nobuild" areas while the spanner is the active weapon.
However it's usually not necessary and it's irritating.
Suggestions:
- Enable the plugin only on maps which have unexpected nobuild areas.
  (cvar or amxx pause/unpause show_nobuild_areas)
- Use a chat or console command to show the nobuild areas on demand.
- Show areas for a few seconds after a build command is sent.
- Same as above, but only if building isn't possible at the current location.
  Perhaps the text message telling this can be used for this purpose.