palace_session_start · Obsidian Palace MCP: Risk & Policy

WHAT IT DOES

What palace_session_start does on Obsidian Palace MCP

AI agents use palace_session_start to create or update resources in Obsidian Palace MCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Obsidian Palace MCP environment.

WHY IT NEEDS A POLICY

Why palace_session_start needs a policy

The tool appears to create a new session record in the Obsidian vault for the current day. This is a Write operation (creating data) with low severity since it's a lightweight initialization action. Confidence is moderate because the description is very terse and uninformative, leaving ambiguity about what 'session' entails.

From the tool's definition 'Start a new session in today' — creates/initializes a new session entry

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

palace_session_start Rate-limited

palace_session_start stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "palace_session_start": {
      "limits": [
        {
          "counter": "palace_session_start_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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 Palace MCP, so you can run agents against it safely.

FAQ

Questions about palace_session_start

What does the palace_session_start tool do? +

Start a new session in today. It is categorised as a Write tool in the Obsidian Palace MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on palace_session_start? +

Register the Obsidian Palace MCP server in PolicyLayer and add a rule for palace_session_start: 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 Palace MCP. Nothing to install.

What risk level is palace_session_start? +

palace_session_start is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit palace_session_start? +

Yes. Add a rate_limit block to the palace_session_start 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 palace_session_start completely? +

Set action: deny in the PolicyLayer policy for palace_session_start. 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 palace_session_start? +

palace_session_start is provided by the Obsidian Palace MCP server (probably-computers/obsidian-palace-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.