mapper_add_validation

Add validation to mapping layer (Pro feature)

SERVERPlugin Hub SOURCE@barnburner121/plugin-hub-mcp

Medium RISK CLASS

Category Write

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/barnburner121-plugin-hub-mcp/mapper-add-validation.md

WHAT IT DOES

What mapper_add_validation does on Plugin Hub

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

RISK

Why mapper_add_validation is rated Medium

An AI agent can call mapper_add_validation faster than any human can review: one bad instruction and it creates or modifies resources in Plugin Hub by the hundred, each call as confident as the last.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs mapper_add_validation safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Plugin Hub, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For mapper_add_validation, this is the rule to start with:

mapper_add_validation Rate-limited

mapper_add_validation 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": {
    "mapper_add_validation": {
      "limits": [
        {
          "counter": "mapper_add_validation_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Plugin Hub, apply this rule, and every mapper_add_validation call is checked against it from then on.

FAQ

Questions about mapper_add_validation

What does the mapper_add_validation tool do? +

Add validation to mapping layer (Pro feature). It is categorised as a Write tool in the Plugin Hub MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on mapper_add_validation? +

Register the Plugin Hub MCP server in PolicyLayer and add a rule for mapper_add_validation: 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 Plugin Hub. Nothing to install.

What risk level is mapper_add_validation? +

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

Can I rate-limit mapper_add_validation? +

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

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

mapper_add_validation is provided by the Plugin Hub MCP server (@barnburner121/plugin-hub-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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