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Digital Gemology: gem identification and gemstone properties

com.digitalgemology/gem-identificationdigitalgemology.comstreamable-httpv1.0.0Scanned

Identify gemstones by refractive index, birefringence, SG, pleochroism and spectrum. Compare 7 gems

4 tools: 3 change things and 1 only read.

Tools: 0 delete, 0 irreversible, 3 write, 1 read.
  • Reads private data · 0
  • Reads text others write · 0
  • Can send data out · 0
  • No findings

Tools listed without sign-in. Remote posture

Anlyon alternative

3 of these tools change something. Run those as governed actions.

Declare what an action changes, and Anlyon puts it under a shared limit, binds every approval to the exact request, and grades the outcome. It works on any HTTPS API you can describe as an action.

Anlyon does not run, proxy or govern this MCP server. A tool your own code calls directly is not routed through Anlyon and is not governed by it.

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Tools

Grouped by what each tool does, most consequential first. Open one for its reasons and full description; descriptions are the publisher's own words.

4 tools

Changes things 3Claude Code: ask
  • absorption_spectrumWhat a hand spectroscope shows for one gemstone: each absorption line and band with its position in nanometres, its cause (for example Cr3+ in ruby) and what it looks like, from Di…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
    What a hand spectroscope shows for one gemstone: each absorption line and band with its position in nanometres, its cause (for example Cr3+ in ruby) and what it looks like, from Digital Gemology's Spectroscope.

    Annotations the server declares

    • title: Absorption spectrum
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • gem_propertiesEverything Digital Gemology measures about one gemstone: refractive index (both rays for doubly refractive stones), birefringence, dispersion, specific gravity, hardness, crystal s…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
    Everything Digital Gemology measures about one gemstone: refractive index (both rays for doubly refractive stones), birefringence, dispersion, specific gravity, hardness, crystal system, critical angle, what a refractometer, polariscope and dichroscope show, its pleochroic colors and the lines and bands a hand spectroscope shows, with links to the free tools.

    Annotations the server declares

    • title: Gemstone properties
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • identify_gemMatch a stone's test readings against the seven gemstones Digital Gemology covers and rank them, saying which reading fits and which does not.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
    Match a stone's test readings against the seven gemstones Digital Gemology covers and rank them, saying which reading fits and which does not. Give any of: refractive index, birefringence, specific gravity, optic character, pleochroism, a spectrum line, or that the refractometer read over the limit. A match is a lead among seven stones only, not an identification.

    Annotations the server declares

    • title: Match gem test readings
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
Only reads 1Show 1 read-only tool
  • compare_gemstonesTwo gemstones side by side, and the tests that tell them apart: refractive index, birefringence (doubling of back facets, polariscope), specific gravity, dispersion (fire), hardnes…No findings

    Why it is in this group

    • The name "compare_gemstones" says "compare": a word for reading.
    Description, as the server wrote it
    Two gemstones side by side, and the tests that tell them apart: refractive index, birefringence (doubling of back facets, polariscope), specific gravity, dispersion (fire), hardness, pleochroism and spectrum, each with the free tool that shows it. For questions like 'how do I tell diamond from moissanite?'.

    Annotations the server declares

    • title: Tell two gemstones apart
    • 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.

Exfil surface

Which tools read private data, which read text someone else can write, and which can send data out. One of each is a path a prompt injection can use.

No private-data, untrusted-input, outbound path in this server alone: no tool is tagged private-data or untrusted-input or outbound.

Reads private data0
Reads files, mail, messages, databases, secrets, calendars or repositories.
Reads text others write0
Brings in text someone else can write: web pages, inbound email, messages, issues and comments.
Can send data out0
Can carry data to people or systems: it sends, posts or publishes, or takes a recipient, channel or URL.

Other servers in the same agent add their own tools to these paths. Audit your whole setup to see them together.

Remote posture

What anyone on the internet sees at the remote endpoint: an anonymous initialize and tools/list, and the public OAuth metadata.

Tools listed without sign-in

Looked at Oct 31, 2026, 23:18 UTC, unchanged since Oct 31, 2026. No credentials were sent and no tool was called. What is looked at.

Reachable
yes
HTTP status of an anonymous initialize
200
tools/list served without credentials
yes
Tools that change things, listed without credentials
3
Protocol version
2025-06-18
WWW-Authenticate on 401
not observed
resource_metadata in WWW-Authenticate
not observed
RFC 9728 protected resource metadata
not observed
Authorization servers
not observed
Legacy HTTP+SSE transport
no
Dynamic client registration
not observed
Client ID metadata documents
not observed
  • WarnThe whole server

    The endpoint served tools/list without credentials, and the list has 3 tools that change things (3 write). Whether a call also works without credentials was not tested: tools are never called.

    Matched text

    https://digitalgemology.com/mcp/gems: tools/list returned 4 tools to an anonymous client, including gem_properties (write), identify_gem (write), absorption_spectrum (write)

    What this check looks for

Findings

Matches of fixed checks, with the text they matched.

No check matched anything in these tool definitions. That is not a safety guarantee.

History

Changes to its tool definitions and to its remote endpoint, newest first.

No change seen yet. Its tools are rescanned every day, and a remote endpoint is looked at once a week.

All changes to this server

Install

Pinned to version 1.0.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http gem-identification https://digitalgemology.com/mcp/gems
claude mcp add --transport http gem-identification https://digitalgemology.com/mcp/gems

Run in a terminal.

Claude Code permissions

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

.claude/settings.json
{
  "permissions": {
    "allow": [
      "mcp__gem-identification__compare_gemstones"
    ],
    "ask": [
      "mcp__gem-identification__gem_properties",
      "mcp__gem-identification__identify_gem",
      "mcp__gem-identification__absorption_spectrum"
    ],
    "deny": []
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. A read that can send data out (it takes a URL, say) asks first too. It assumes the server is installed as gem-identification. Review it before you use it.

Pin

Keep the decision: fail CI when the tools change, follow every change, or show a badge.

Pin in CI

Fail a build when the tools you reviewed are not the tools the server serves today.

curl -s "https://anlyon.dev/api/v1/servers/com.digitalgemology/gem-identification/verify?hash=cb874e6d9da4a25d191bee4b6256a84ab955dc8c04133af0c5c8d603c303f661" | jq -e '.changed == false'

Pinned hash cb874e6d9da4, from Oct 31, 2026, 23:18 UTC.

Watch

Get told when its tools change: a new tool, a new description, a new class.

https://anlyon.dev/servers/com.digitalgemology/gem-identification/changes.xml

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Badge

anlyon.dev badge for com.digitalgemology/gem-identification
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Source: MCP Registry · repository. Synced Oct 31, 2026, 23:17 UTC.