update_workout · Hevy MCP: Risk & Policy

WHAT IT DOES

What update_workout does on Hevy

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

WHY IT NEEDS A POLICY

Why update_workout needs a policy

The tool modifies existing workout data by replacing exercises, which is a reversible write operation. It does not delete the workout itself (would be Destructive) nor execute arbitrary code (would be Execute). The severity is medium because misuse could corrupt a user's fitness tracking data, but the operation is reversible—the user can update the workout again to fix it.

From the tool's definition Tool name 'update_workout' and description 'Update an existing workout. Replaces all exercises' indicate modification of existing data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_workout Rate-limited

update_workout 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": {
    "update_workout": {
      "limits": [
        {
          "counter": "update_workout_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 Hevy, so you can run agents against it safely.

FAQ

Questions about update_workout

What does the update_workout tool do? +

Update an existing workout. Replaces all exercises. It is categorised as a Write tool in the Hevy MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update_workout? +

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

What risk level is update_workout? +

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

Can I rate-limit update_workout? +

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

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

update_workout is provided by the Hevy MCP server (srdjancodes/hevy-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.