join_simul · Lichess Integration MCP: Risk & Policy

WHAT IT DOES

What join_simul does on Lichess Integration

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

PARAMETERS

Parameter	Type	Required	Description
`simulId`	string	—	ID of the simul

Parameters from the server's own tool schema.

WHY IT NEEDS A POLICY

Why join_simul needs a policy

Joining a simul creates a participation record and commits the user to an event on the Lichess platform. This is a reversible write action (the user could potentially withdraw), not destructive or financial. Severity is medium because an AI agent could join simuls on behalf of the user without explicit consent, potentially affecting their reputation or schedule.

From the tool's definition Join a simul — joining a simultaneous chess exhibition commits the user to participate in an event

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

join_simul Rate-limited

join_simul 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": {
    "join_simul": {
      "limits": [
        {
          "counter": "join_simul_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 Lichess Integration, so you can run agents against it safely.

FAQ

Questions about join_simul

What does the join_simul tool do? +

Join a simul. It is categorised as a Write tool in the Lichess Integration MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

What parameters does join_simul accept? +

join_simul accepts 1 parameter: simulId. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on join_simul? +

Register the Lichess Integration MCP server in PolicyLayer and add a rule for join_simul: 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 Lichess Integration. Nothing to install.

What risk level is join_simul? +

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

Can I rate-limit join_simul? +

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

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

join_simul is provided by the Lichess Integration MCP server (karayaman/lichess-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.