json_validate_schema

Generate JSON schema validation

SERVERPlugin Hub SOURCE@barnburner121/plugin-hub-mcp

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/barnburner121-plugin-hub-mcp/json-validate-schema.md

WHAT IT DOES

What json_validate_schema does on Plugin Hub

AI agents call json_validate_schema to retrieve information from Plugin Hub without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

RISK

Why json_validate_schema is rated Low

Even though json_validate_schema only reads data, uncontrolled read access leaks sensitive information and racks up API costs: an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs json_validate_schema 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 json_validate_schema, this is the rule to start with:

json_validate_schema Allowed

json_validate_schema is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "json_validate_schema": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

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

FAQ

Questions about json_validate_schema

What does the json_validate_schema tool do? +

Generate JSON schema validation. It is categorised as a Read tool in the Plugin Hub MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on json_validate_schema? +

Register the Plugin Hub MCP server in PolicyLayer and add a rule for json_validate_schema: 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 json_validate_schema? +

json_validate_schema is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit json_validate_schema? +

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

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

json_validate_schema 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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