render_mermaid_diagrams · Obsidian Markdown Lint MCP

WHAT IT DOES

What render_mermaid_diagrams does on Obsidian Markdown Lint

AI agents invoke render_mermaid_diagrams to trigger actions in Obsidian Markdown Lint. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why render_mermaid_diagrams needs a policy

Rendering Mermaid diagrams involves executing a diagram-rendering engine (e.g., mermaid-js) against code blocks extracted from markdown. This is an execution action — it runs code/processes against arbitrary input — rather than a simple read or write.

From the tool's definition 'render each to SVG' — the tool executes a rendering pipeline that processes mermaid code blocks from markdown content into SVG output, triggering external rendering operations

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

render_mermaid_diagrams Rate-limited

render_mermaid_diagrams stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "render_mermaid_diagrams": {
      "limits": [
        {
          "counter": "render_mermaid_diagrams_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Obsidian Markdown Lint, so you can run agents against it safely.

FAQ

Questions about render_mermaid_diagrams

What does the render_mermaid_diagrams tool do? +

Extract all mermaid code blocks from markdown content, render each to SVG,. It is categorised as a Execute tool in the Obsidian Markdown Lint MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on render_mermaid_diagrams? +

Register the Obsidian Markdown Lint MCP server in PolicyLayer and add a rule for render_mermaid_diagrams: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Obsidian Markdown Lint. Nothing to install.

What risk level is render_mermaid_diagrams? +

render_mermaid_diagrams is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit render_mermaid_diagrams? +

Yes. Add a rate_limit block to the render_mermaid_diagrams rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block render_mermaid_diagrams completely? +

Set action: deny in the PolicyLayer policy for render_mermaid_diagrams. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides render_mermaid_diagrams? +

render_mermaid_diagrams is provided by the Obsidian Markdown Lint MCP server (psenger/obsidian-markdown-lint-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.