Sienna, Knobs.co hardware advisor

At a glance

Runs where

On their server. What you send to it goes to them.

What you need

Nothing: it answered without a login

Tools

7 tools

Its own safety labels

7 read-only

Memory it takes

About 940 tokens of your AI's memory, just for its tool descriptions

Largest answer

About 15 KB in our test

Tools that look alike

1 pair of tools with nearly the same description, so the AI may pick the wrong one

Speed

Average answer in our test: 1.1 s

Tokens are an estimate: the characters in its tool names, descriptions and inputs, divided by 4. The exact number depends on your AI model. Safety labels are what the server says about itself. From our latest test, 6 Nov 2026.

Is Sienna, Knobs.co hardware advisor MCP server safe?

• None of the hidden-instruction wordings we know were found in its 7 tool descriptions.
• Its error messages showed no secrets or internal details.
• All 7 of its tools are labeled read-only.
• Overall it scored 86/100 on 6 Nov 2026.

A test can only see what the server shows from outside, not what it does with your data behind the scenes. Connect servers from makers you trust.

What this test does not check

• Its source code and packages.
• What a tool quietly does behind the scenes, such as writing a file or calling another service.
• Instructions hidden inside live tool answers. We only look for those in tool descriptions.
• Hidden instructions worded in a way our list doesn't know yet.
• Tools that could change something. Those are read, never run.

What QAmcp can and can't see · How to tell if an MCP server is safe · Hidden instructions · Prompt injection

Known security advisories

It lists no public code, so there is nothing to look up in GitHub Security Advisories or OSV.dev. QAmcp tests how a server behaves. It does not scan source code.

What it can do

7 tools, in the server's own words.

Test results

Safe mode: only tools labeled read-only were run. How the test works

• !
  Ready for the newest MCP version

  1 warning

  • !Uses an older MCP version (2025-11-25). It works today, but it isn't on the July 2026 version (2026-07-28) yet.
  note
• !
  Every tool is described

  3 warnings

  • !search: Inputs with no description: query
  • !fetch: Inputs with no description: id
  • !search and fetch have nearly the same description (62% of their words are shared; the only difference: "result", "where" vs "document", "text", "metadata"), so an AI may not know which to pick
  note
• !
  Fast enough

  1 warning

  • !ask_sienna: Slowest tool: ask_sienna (4.5 s): users will notice the wait
  • and 3 more
  note
• !
  Follows MCP best practices (not scored yet)

  2 tips (not scored)

  • !Very common tool names: search, fetch. Next to other servers' tools the AI may mix them up; a short prefix helps (like "github_search" instead of "search").
  • !1 tool answers with structured data but doesn't declare its shape (outputSchema): search. If those answers change shape, nothing can catch it; with a schema, every answer is checked.
  note
• ✓
  ConnectsConnected in 584 ms
  pass
• ✓
  Lists its toolsFound 7 tools
  pass
• ✓
  Tools are labeled safe or dangerousEvery tool has a safety label
  pass
• ✓
  No known hidden instructionsNone of the hidden-instruction wordings we know were found in tool descriptions. New wordings can get past this check.
  pass
• ✓
  Tools work with good inputs

  All good

  • ✓ask_sienna: Worked (4.5 s)
  • ✓search_catalog: Worked (841 ms)
  • ✓get_product: Answered with an error, probably because of our sample input: No product with handle "test". Use search_catalog to find the handle.
  • ✓sizing_guide: Worked (278 ms)
  • ✓store_info: Worked (292 ms)
  • ✓search: Worked (571 ms)
  • ✓fetch: Answered with an error, probably because of our sample input: No product with handle "test". Use search_catalog to find the handle.
  pass
• ✓
  Bad inputs give a clean error

  All good

  • ✓ask_sienna: Refused missing required input "question" with a clear error
  • ✓ask_sienna: Refused wrong type for "question" with a clear error
  • ✓search_catalog: Refused missing required input "query" with a clear error
  • ✓search_catalog: Refused wrong type for "query" with a clear error
  • ✓get_product: Refused missing required input "handle" with a clear error
  • ✓get_product: Refused wrong type for "handle" with a clear error
  • ✓search: Refused missing required input "query" with a clear error
  • ✓search: Refused wrong type for "query" with a clear error
  • and 2 more
  pass
• ✓
  Tools work togethersearch_catalog → get_product: get_product found what search_catalog returned (handle = "berenson-1288-1mdb-p-tailored-traditional-128mm-cc-modern-b…")
  pass
• ✓
  No secrets leakedChecked 17 error messages: no secrets or internal details
  pass

Test it yourself

Free and open source. Same checks, same score.

Show this score on GitHub

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Score over time

• 6 Nov 202686

One test so far. New tests will show here.

Reviews

Coming soon: reviews from people who use Sienna, Knobs.co hardware advisor, signed in with GitHub, one per person. Reviews never change the score.