json_type

Get the type of JSON value at path. Args: key: The name of the key path: The path in the JSON document (optional, defaults to root) Returns: JSON type or error message

SERVERAWS SOURCE@awslabs/mcp

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade F, identity verified Pull the record →

This record as markdown: /tools/aws/json-type.md

WHAT IT DOES

What json_type does on AWS

AI agents call json_type to retrieve information from AWS 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_type is rated Low

This tool only reads and returns the type of a JSON value at a specified path. It performs no writes, executions, or deletions. The blast radius if misused is minimal as it only exposes type metadata.

From the tool's definition "Get the type of JSON value at path" — purely retrieves type information, no side effects

Risk signalsAdmin/system-level operation

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs json_type safely

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

json_type Allowed

json_type 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_type": {}
  }
}

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

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

FAQ

Questions about json_type

What does the json_type tool do? +

Get the type of JSON value at path. Args: key: The name of the key path: The path in the JSON document (optional, defaults to root) Returns: JSON type or error message. It is categorised as a Read tool in the AWS MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on json_type? +

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

What risk level is json_type? +

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

Can I rate-limit json_type? +

Yes. Add a rate_limit block to the json_type 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_type completely? +

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

json_type is provided by the AWS MCP server (@awslabs/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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