coord_join_team · Session Coord MCP: Risk & Policy

WHAT IT DOES

What coord_join_team does on Session Coord

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

WHY IT NEEDS A POLICY

Why coord_join_team needs a policy

This tool modifies state by associating the current session with a team, which is a reversible write operation. It creates a membership relationship but does not delete data, execute code, or involve financial transactions. The blast radius is low as it only affects session coordination metadata within a local-first coordination server.

From the tool's definition Join a development team with the current session

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

coord_join_team Rate-limited

coord_join_team 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": {
    "coord_join_team": {
      "limits": [
        {
          "counter": "coord_join_team_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 Session Coord, so you can run agents against it safely.

FAQ

Questions about coord_join_team

What does the coord_join_team tool do? +

Join a development team with the current session. It is categorised as a Write tool in the Session Coord MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on coord_join_team? +

Register the Session Coord MCP server in PolicyLayer and add a rule for coord_join_team: 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 Session Coord. Nothing to install.

What risk level is coord_join_team? +

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

Can I rate-limit coord_join_team? +

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

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

coord_join_team is provided by the Session Coord MCP server (lingfeng-vels/session-coord-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.