Human Mailbox

Is Human Mailbox MCP server safe?

• No hidden instructions were found in its tool descriptions.
• Its error messages showed no secrets or internal details.
• 16 of its 32 tools are labeled read-only; the others may change or send things.
• Overall it scored 83/100 on 30 Oct 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

32 tools, in the server's own words.

and 8 more

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

  24 warnings

  • !register_mailbox: Inputs with no description: agent_name, operator_email, accept_terms, operator_type, operator_country, agent_model
  • !start_demo: Inputs with no description: agent_name, agent_model, found_via
  • !express_interest: Inputs with no description: kind, name, email, country_wanted, use_case, found_via
  • !buy_bundle: Inputs with no description: bundle
  • !pay_item: Inputs with no description: id
  • !announce_shipment: Inputs with no description: carrier, tracking, sender, description, expected_at, instructions, open_mode
  • !list_shipments: Inputs with no description: status
  • !list_items: Inputs with no description: status
  • and 16 more
  note
• !
  Tools are labeled safe or dangerous

  1 warning

  • !15 of 32 tools have no safety label (read-only or dangerous): register_mailbox, start_demo, express_interest, buy_bundle, pay_item, announce_shipment, accept_quote, cancel_request, reveal_codes, request_invoice, contact_human, pay_subscript
  note
• !
  Follows MCP best practices (not scored yet)

  2 tips (not scored)

  • !16 tools not labeled read-only don't say whether running them twice is safe (idempotentHint): register_mailbox, start_demo, express_interest, buy_bundle, pay_item, announce_shipment and 10 more
  • !14 tools don't say whether they reach outside services like the web (openWorldHint): start_demo, express_interest, buy_bundle, pay_item, announce_shipment, accept_quote and 8 more
  note
• ✓
  ConnectsConnected in 211 ms
  pass
• ✓
  Lists its toolsFound 32 tools
  pass
• ✓
  No hidden instructionsNo hidden instructions found in tool descriptions
  pass
• ✓
  Tools work with good inputs

  All good

  • ✓get_prices: Worked (353 ms)
  • ✓get_account: Answered with an error, probably because of our sample input: {"error":"unauthorized","message":"Missing or wrong API key. Call register_mailbox first, then send \"Authorization: Bearer <api_key>\" (or…
  • ✓get_address: Answered with an error, probably because of our sample input: {"error":"unauthorized","message":"Missing or wrong API key. Call register_mailbox first, then send \"Authorization: Bearer <api_key>\" (or…
  • ✓list_shipments: Answered with an error, probably because of our sample input: {"error":"unauthorized","message":"Missing or wrong API key. Call register_mailbox first, then send \"Authorization: Bearer <api_key>\" (or…
  • ✓list_items: Answered with an error, probably because of our sample input: {"error":"unauthorized","message":"Missing or wrong API key. Call register_mailbox first, then send \"Authorization: Bearer <api_key>\" (or…
  • ✓get_item: Answered with an error, probably because of our sample input: {"error":"unauthorized","message":"Missing or wrong API key. Call register_mailbox first, then send \"Authorization: Bearer <api_key>\" (or…
  • ✓list_requests: Answered with an error, probably because of our sample input: {"error":"unauthorized","message":"Missing or wrong API key. Call register_mailbox first, then send \"Authorization: Bearer <api_key>\" (or…
  • ✓get_request: Answered with an error, probably because of our sample input: {"error":"unauthorized","message":"Missing or wrong API key. Call register_mailbox first, then send \"Authorization: Bearer <api_key>\" (or…
  • and 24 more
  pass
• ✓
  Bad inputs give a clean error

  All good

  • ✓get_account: Refused wrong type for "api_key" with a clear error
  • ✓get_address: Refused wrong type for "style" with a clear error
  • ✓list_shipments: Refused wrong type for "status" with a clear error
  • ✓list_items: Refused wrong type for "status" with a clear error
  • ✓get_item: Refused missing required input "id" with a clear error
  • ✓get_item: Refused wrong type for "id" with a clear error
  • ✓list_requests: Refused wrong type for "status" with a clear error
  • ✓get_request: Refused missing required input "id" with a clear error
  • and 11 more
  pass
• ✓
  Fast enough

  All good

  • ✓Connecting took 211 ms
  • ✓Listing tools took 43 ms
  • ✓Average tool answer: 54 ms
  • ✓get_prices: Slowest tool: get_prices (353 ms)
  pass
• ✓
  No secrets leakedChecked 42 error messages: no secrets or internal details
  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

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Score over time

• 30 Oct 202683

One test so far. New tests will show here.

Reviews

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