Federal Register

Is Federal Register MCP server safe?

• No hidden instructions were found in its tool descriptions.
• Its error messages showed no secrets or internal details.
• All 8 of its tools are labeled read-only.
• Overall it scored 80/100 on 28 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

8 tools, in the server's own words.

Test results

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

• ✕
  Bad inputs give a clean error

  1 failed

  • ✕far_case_history: Broke the MCP rules on wrong type for "docket_id": its reply has the wrong shape
  • and 10 more
  fail
• !
  Every tool is described

  8 warnings

  • !search_documents: Inputs with no description: agencies, doc_types, term, docket_id, regulation_id_number, pub_date_gte, pub_date_lte, comment_date_gte, comment_date_lte, effective_date_gte, effective_date_lte, correction, significant, cfr_title, cfr_part, pr
  • !get_document: Inputs with no description: document_number
  • !get_documents_batch: Inputs with no description: document_numbers
  • !get_facet_counts: Inputs with no description: facet, agencies, doc_types, term, pub_date_gte, pub_date_lte, cfr_title, cfr_part, presidential_document_type
  • !get_public_inspection: Inputs with no description: agency_filter, keyword_filter, limit
  • !list_agencies: Inputs with no description: query, include_detail
  • !open_comment_periods: Inputs with no description: agencies, term, limit, far_council
  • !far_case_history: Inputs with no description: docket_id
  note
• !
  Tools work with good inputs

  3 warnings

  • !get_public_inspection: Answered with about 182 KB of text. Many AI apps cut off tool answers this big, so the AI may never see the end of it.
  • !list_agencies: Answered with about 155 KB of text. Many AI apps cut off tool answers this big, so the AI may never see the end of it.
  • !far_case_history: Answered with about 407 KB of text. Many AI apps cut off tool answers this big, so the AI may never see the end of it.
  • –open_comment_periods: Not run: labeled read-only, but its name starts with "open", which usually means it changes something. Skipped to be safe: if it only reads, a clearer name helps AI apps too, or test again with --owner
  • and 4 more
  note
• ✓
  ConnectsConnected in 449 ms
  pass
• ✓
  Ready for the newest MCP versionUses the latest MCP version (2026-07-28)
  pass
• ✓
  Lists its toolsFound 8 tools
  pass
• ✓
  Tools are labeled safe or dangerousEvery tool has a safety label
  pass
• ✓
  No hidden instructionsNo hidden instructions found in tool descriptions
  pass
• ✓
  Fast enough

  All good

  • ✓Connecting took 449 ms
  • ✓Listing tools took 125 ms
  • ✓Average tool answer: 372 ms
  • ✓far_case_history: Slowest tool: far_case_history (1.0 s)
  pass
• ✓
  No secrets leakedChecked 25 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 ()

  • –Could not list resources: the server limited our requests (HTTP 429)
  • –Could not list prompts: the server limited our requests (HTTP 429)
  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

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Score over time

• 28 Oct 202680

One test so far. New tests will show here.

Reviews

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