BinaryBirthday

Is BinaryBirthday 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 6 of its tools are labeled read-only.
• Overall it scored 83/100 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

6 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 (2025-06-18). It works today, but it isn't on the July 2026 version (2026-07-28) yet.
  note
• !
  Every tool is described

  1 warning

  • !number_to_binary and binary_to_number have nearly the same description (100% of their words are shared; the descriptions are identical), so an AI may not know which to pick
  note
• !
  Bad inputs give a clean error

  3 warnings

  • !text_to_binary: Accepted missing required input "text" without complaining
  • !text_to_binary: Accepted wrong type for "text" without complaining
  • !number_to_binary: Accepted wrong type for "number" without complaining
  • and 8 more
  note
• ✓
  ConnectsConnected in 478 ms
  pass
• ✓
  Lists its toolsFound 6 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

  • ✓date_to_binary: Answered with an error, probably because of our sample input: { "error": "Use the date format YYYY-MM-DD, like 1990-06-15." } {"error":"Use the date format YYYY-MM-DD, like 1990-06-15."}
  • ✓text_to_binary: Worked (91 ms)
  • ✓binary_to_text: Answered with an error, probably because of our sample input: { "error": "Binary can only contain 0s, 1s and spaces." } {"error":"Binary can only contain 0s, 1s and spaces."}
  • ✓number_to_binary: Answered with an error, probably because of our sample input: { "error": "Enter a whole number, like 42 or 2025." } {"error":"Enter a whole number, like 42 or 2025."}
  • ✓binary_to_number: Answered with an error, probably because of our sample input: { "error": "Binary can only contain 0s and 1s." } {"error":"Binary can only contain 0s and 1s."}
  • ✓suggest_binary_gifts: Worked (64 ms)
  pass
• ✓
  Fast enough

  All good

  • ✓Connecting took 478 ms
  • ✓Listing tools took 112 ms
  • ✓Average tool answer: 76 ms
  • ✓text_to_binary: Slowest tool: text_to_binary (91 ms)
  pass
• ✓
  No secrets leakedChecked 12 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
• –
  Tools work togetherNo tool's answer could be fed into another tool, so there were no chains to test (not counted either way)
  not tested

Test it yourself

Free and open source. Same checks, same score.

Show this score on GitHub

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Score over time

• 1 Nov 202683

One test so far. New tests will show here.

Reviews

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