json_schema_validate
JSON Schema Validator — Validate a JSON value against a JSON Schema (bounded draft-07-ish subset: type/enum/required/properties/items/min-max/pattern) and list every violation.
This record as markdown: /tools/com-wingmanprotocol-agent-gateway/json-schema-validate.md
What json_schema_validate does on Gateway
AI agents call json_schema_validate to retrieve information from Gateway without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
schema | object | Yes | JSON Schema object describing the expected shape |
instance | object | array | string | number | boolean | null | Yes | The JSON value to validate against schema (any JSON type) |
Parameters from the server's own tool schema.
Why json_schema_validate is rated Low
This tool performs data validation only. It reads and analyzes JSON against schema constraints, producing a report of violations. There are no side effects, state changes, data creation, deletion, or command execution. The worst case of misuse is that an agent receives accurate or inaccurate validation feedback, which has minimal blast radius. Classification as Read is appropriate.
From the tool's definition Tool description states it 'Validate[s] a JSON value against a JSON Schema' and 'list[s] every violation.' No modifications, deletions, or external executions are mentioned.
Risk signalsBulk/mass operation — affects multiple targets
Attacks that exploit this kind of access
The rule that runs json_schema_validate safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Gateway, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For json_schema_validate, this is the rule to start with:
json_schema_validate is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Gateway, apply this rule, and every json_schema_validate call is checked against it from then on.
Questions about json_schema_validate
JSON Schema Validator — Validate a JSON value against a JSON Schema (bounded draft-07-ish subset: type/enum/required/properties/items/min-max/pattern) and list every violation. It is categorised as a Read tool in the Gateway MCP Server, which means it retrieves data without modifying state.
json_schema_validate accepts 2 parameters: schema, instance. Required: schema, instance. The full parameter table on this page comes from the server's own tool schema.
Register the Gateway MCP server in PolicyLayer and add a rule for json_schema_validate: 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 Gateway. Nothing to install.
json_schema_validate is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the json_schema_validate 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.
Set action: deny in the PolicyLayer policy for json_schema_validate. 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.
json_schema_validate is provided by the Gateway MCP server (https://wingmanprotocol.com/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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