Machine Schema

Is Machine Schema MCP server safe?

• None of the hidden-instruction wordings we know were found in its tool descriptions.
• Its error messages showed no secrets or internal details.
• All 10 of its tools are labeled read-only.
• Overall it scored 90/100 on 1 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 it can do

10 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

  8 warnings

  • !search_entries: Inputs with no description: type, limit
  • !find_hardware: Inputs with no description: category, min_payload_kg, min_reach_mm, max_repeatability_mm, limit
  • !compare: Inputs with no description: ids
  • !check_limits: Inputs with no description: tcp_speed_mm_s, ambient_temp_c
  • !get_related: Inputs with no description: id, limit
  • !lookup_alarm: Inputs with no description: code
  • !calculate_metric: Inputs with no description: inputs
  • !get_schema: Inputs with no description: type
  note
• ✓
  ConnectsConnected in 310 ms
  pass
• ✓
  Lists its toolsFound 10 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

  • ✓search_entries: Worked (338 ms)
  • ✓get_entry: Answered with an error, probably because of our sample input: No entry with id "test". Use search_entries to find ids.
  • ✓find_hardware: Worked (216 ms)
  • ✓list_facets: Worked (251 ms)
  • ✓compare: Answered with an error, probably because of our sample input: Invalid arguments: ✖ Too small: expected array to have >=2 items → at ids
  • ✓check_limits: Answered with an error, probably because of our sample input: No hardware entry with id "test".
  • ✓get_related: Worked (187 ms)
  • ✓lookup_alarm: Worked (192 ms)
  • and 2 more
  pass
• ✓
  Bad inputs give a clean error

  All good

  • ✓search_entries: Refused missing required input "query" with a clear error
  • ✓search_entries: Refused wrong type for "query" with a clear error
  • ✓get_entry: Refused missing required input "id" with a clear error
  • ✓get_entry: Refused wrong type for "id" with a clear error
  • ✓find_hardware: Refused wrong type for "category" with a clear error
  • ✓compare: Refused missing required input "ids" with a clear error
  • ✓compare: Refused wrong type for "ids" with a clear error
  • ✓check_limits: Refused missing required input "id" with a clear error
  • and 9 more
  pass
• ✓
  Tools work together

  4 chains working

  • ✓search_entries → get_entry: get_entry found what search_entries returned (id = "ur-c296a7")
  • ✓search_entries → get_related: get_related found what search_entries returned (id = "ur-c296a7")
  • ✓find_hardware → get_entry: get_entry found what find_hardware returned (id = "abb-gofa-5")
  • ✓find_hardware → get_related: get_related found what find_hardware returned (id = "abb-gofa-5")
  pass
• ✓
  Fast enough

  All good

  • ✓Connecting took 310 ms
  • ✓Listing tools took 48 ms
  • ✓Average tool answer: 206 ms
  • ✓search_entries: Slowest tool: search_entries (338 ms)
  pass
• ✓
  No secrets leakedChecked 35 error messages: no secrets or internal details
  pass
• ✓
  Follows MCP best practices (not scored yet)Tool names, safety labels and tool list size follow the MCP guide
  pass
• ✓
  Resources and prompts work

  All good (2 templates, 4 prompts)

  • –Could not list resources: we got an error we could not interpret
  • ✓machineschema://{type}/{id}: A made-up value gets a clean error (machineschema://qamcp-test/qamcp-test)
  • ✓machineschema://schema/{type}: A made-up value gets a clean error (machineschema://schema/qamcp-test)
  • ✓An address that does not exist gets a clean "not found" error
  • ✓Opened 4 of 4 prompts
  pass

Test it yourself

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Score over time

• 1 Nov 202690

One test so far. New tests will show here.

Reviews

Coming soon: reviews from people who use Machine Schema, signed in with GitHub, one per person. Reviews never change the score.