validate_json
utilpeek: Validate JSON against a JSON Schema. To pull JSON out of prose use extract_json_with_schema; to convert formats use convert_data. Returns whether a JSON value is valid against a JSON Schema (draft from $schema, default 2020-12; 2019-09, 7, 6, 4 and 3 recognised), with up to 100 errors (...
This record as markdown: /tools/dev-tanod-tanod/validate-json.md
What validate_json does on Tanod
AI agents call validate_json to retrieve information from Tanod 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 (draft from $schema; default 2020-12). Remote $ref documents are refused, never fetched. |
instance | object | array | string | number | integer | boolean | null | Yes | Any JSON value to validate. |
Parameters from the server's own tool schema.
Why validate_json is rated Low
Even though validate_json 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
The rule that runs validate_json safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Tanod, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For validate_json, this is the rule to start with:
validate_json 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 Tanod, apply this rule, and every validate_json call is checked against it from then on.
Questions about validate_json
utilpeek: Validate JSON against a JSON Schema. To pull JSON out of prose use extract_json_with_schema; to convert formats use convert_data. Returns whether a JSON value is valid against a JSON Schema (draft from $schema, default 2020-12; 2019-09, 7, 6, 4 and 3 recognised), with up to 100 errors (instance path, schema path, message, validator) and the formats checked. Remote $ref documents are refused (422 remote_ref_forbidden), never fetched. Input: instance and schema; together at most 1 MB. An invalid schema is a 422 invalid_schema. Parsed in an isolated, resource-limited child process without network; input over its limits is a 422 (not charged). Typically under 0.5 s. Price: USD 0.001. Free: 10 utilpeek calls per IP per UTC day. The submitted text is never logged or stored. Docs: https://tanod.dev/learn/json-schema-validation-api.html. It is categorised as a Read tool in the Tanod MCP Server, which means it retrieves data without modifying state.
validate_json 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 Tanod MCP server in PolicyLayer and add a rule for validate_json: 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 Tanod. Nothing to install.
validate_json 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 validate_json 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 validate_json. 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.
validate_json is provided by the Tanod MCP server (https://tanod.dev/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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