swap_exercise · Pelaris MCP: Risk & Policy

WHAT IT DOES

What swap_exercise does on Pelaris

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

WHY IT NEEDS A POLICY

Why swap_exercise needs a policy

The tool can modify a planned session by swapping an exercise, which is a reversible write operation. It also has a read component (finding alternatives with rationale), but the primary actionable capability is modifying existing planned session data. Since Write is more severe than Read, it takes precedence. Severity is medium as it affects training plans but is reversible.

From the tool's definition swap an exercise in a planned session

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

swap_exercise Rate-limited

swap_exercise 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": {
    "swap_exercise": {
      "limits": [
        {
          "counter": "swap_exercise_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 Pelaris, so you can run agents against it safely.

FAQ

Questions about swap_exercise

What does the swap_exercise tool do? +

Find alternative exercises with rationale, or swap an exercise in a planned session. Returns 3 suggestions based on movement pattern. It is categorised as a Write tool in the Pelaris MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on swap_exercise? +

Register the Pelaris MCP server in PolicyLayer and add a rule for swap_exercise: 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 Pelaris. Nothing to install.

What risk level is swap_exercise? +

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

Can I rate-limit swap_exercise? +

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

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

swap_exercise is provided by the Pelaris MCP server (thedonk/pelaris-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.