Some Sidekick tools are missing or fail to load

Some of Sidekick’s tools stop working while the rest keep going — most often the health check (“sidekick health”), layout inspection, and font measurements. You might see it in one of these ways:

• You ask for “sidekick health” and get nothing back — no answer, no error, as though the tool doesn’t exist.

• Your AI assistant reports an error like:

  Tool ‘get_health’ has an invalid outputSchema: JSON Schema declares an unsupported dialect (“$schema”: “http://json-schema.org/draft-07/schema#”). The default validator supports JSON Schema 2020-12 only.

Everything else in Sidekick keeps working, which is exactly what makes this confusing — nothing obviously fails, a few tools are simply not there.

What’s happening

This isn’t specific to Sidekick, and it isn’t a mistake in how Sidekick describes its tools — those descriptions follow the specification exactly. In August 2026, the software that AI assistants use to talk to tools started validating tool descriptions more strictly, and began setting aside a form that the specification actually allows. A handful of Sidekick’s tools used that form, so the stricter check quietly dropped them rather than reading them. It’s a shared change — it took out tools across many unrelated products at the same time, including some of Anthropic’s own.

Because the tools are dropped inside the assistant — before any request reaches Sidekick — nothing shows up as a failure. They’re just missing.

The fix: update to 1.0.25 or later

Sidekick 1.0.25 describes its tools in a different form — equally valid, and one the stricter check accepts — so assistants keep them. Getting it has one wrinkle worth knowing:

This update needs a reinstall. Most Sidekick updates arrive on their own, but this fix lives in the part that’s installed on your computer rather than the part that updates itself — so waiting, or just restarting, won’t pick it up. Download the latest version from the install page and run it. Your settings and your Adobe Exchange plugin stay exactly as they are.

A couple of things to know while you do it:

• “sidekick health” won’t work until this is fixed — it’s one of the affected tools — so don’t rely on it to check your version beforehand. Once the reinstall is done and the tool answers again, you’ll know you’re on the fixed build.
• On Windows, make sure the assistant fully quits before you reopen it. Closing the window usually leaves it running in the system tray, so it keeps serving the old version. Quit it from the tray icon (or Task Manager), then open it again after installing.

Still missing after updating?

If a tool is still missing once you’re on the latest version, email us at [email protected] with your platform (Mac or Windows) and which AI assistant you’re using, and we’ll help you track it down.