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Mithrandir — free MCP gateway test

by Hyhyr2 · remote · no sign-in to list tools · v0.20.0 · published by GitHub user Hyhyr2

Observe MCP tools, verify repeated reads, then try bounded exact reuse for free.

Deletes · 1Changes · 2
CompareRegistry entry

3 tools: 1 can delete or cancel things and 2 change things.

Scanned Oct 21, 2026

1 check matched something in the tool definitions. No finding is not a safety guarantee. How the checks work.

claude mcp add --transport http mithrandir https://mithrandir-production.up.railway.app/mcp

Findings

Matches of fixed checks, with the text they matched.

1 warn
  • Warnmithrandir_demo

    The server marks "mithrandir_demo" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

    Matched text

    annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":false}; The description's first verb is "run": a word for a change.

    What this check looks for

Tools

Open a tool for its reasons and full description. Descriptions are the publisher's own words, shown as they are.

3 tools

Deletes or cancels 1Claude Code: deny
  • mithrandir_gateway_trial_startStart a bounded free gateway test.No findings

    Why it is in this group

    • The name "mithrandir_gateway_trial_start" says "start": a word for a change.
    • The server marks it destructive (destructiveHint: true).
    Description, as the server wrote it
    Start a bounded free gateway test. Connect your public HTTPS MCP server, then approve safe reads and verify repetition before free Optimize activation.

    Annotations the server declares

    • readOnlyHint: false
    • destructiveHint: true
    • idempotentHint: false
    • openWorldHint: false
Changes things 2Claude Code: ask
  • mithrandir_demoRun a free isolated synthetic Reuse Autopilot demonstration.1 finding

    Why it is in this group

    • The description's first verb is "run": a word for a change.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.

    Findings

    • Warn

      The server marks "mithrandir_demo" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

      Matched text

      annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":false}; The description's first verb is "run": a word for a change.

      What this check looks for
    Description, as the server wrote it
    Run a free isolated synthetic Reuse Autopilot demonstration. No production account, upload, payment or private data is used. Compare unchanged, one-partition-changed and missing-source behavior before onboarding.

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • mithrandir_security_profileFree machine-readable description of the v17 Cognitive Membrane trust model: origin-bound authority, task-scoped exact-call capabilities, replay protection, egress control and two-…No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Free machine-readable description of the v17 Cognitive Membrane trust model: origin-bound authority, task-scoped exact-call capabilities, replay protection, egress control and two-phase effectful actions. This is a security contract description, not proof that a deployment is vulnerability-free.

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false

This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.

Install

Pinned to version 0.20.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http mithrandir https://mithrandir-production.up.railway.app/mcp

Run in a terminal.

Claude Code permissions

Allow the reads, ask before a change, deny the deletes. Paste into .claude/settings.json.

.claude/settings.json
{
  "permissions": {
    "allow": [],
    "ask": [
      "mcp__mithrandir__mithrandir_demo",
      "mcp__mithrandir__mithrandir_security_profile"
    ],
    "deny": [
      "mcp__mithrandir__mithrandir_gateway_trial_start"
    ]
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. It assumes the server is installed as mithrandir. Review it before you use it.