set_add

Add member to set. Args: key: The name of the key member: Member to add Returns: Success message or error message

SERVERAWS SOURCE@awslabs/mcp

Medium RISK CLASS

Category Write

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity verified Pull the record →

This record as markdown: /tools/aws/set-add.md

WHAT IT DOES

What set_add does on AWS

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

RISK

Why set_add is rated Medium

This tool creates or modifies data in a set structure by adding members, which is a reversible write operation. Severity is medium because modifying set membership could affect access control or configuration state, though the operation is not destructive or financial.

From the tool's definition Tool description explicitly states "Add member to set" with arguments for key and member, indicating data modification. Returns "Success message or error message" confirming state change.

Attacks that exploit this kind of access

RECOMMENDED RULE

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

set_add Rate-limited

set_add 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": {
    "set_add": {
      "limits": [
        {
          "counter": "set_add_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 AWS, apply this rule, and every set_add call is checked against it from then on.

FAQ

Questions about set_add

What does the set_add tool do? +

Add member to set. Args: key: The name of the key member: Member to add Returns: Success message or error message. It is categorised as a Write tool in the AWS MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on set_add? +

Register the AWS MCP server in PolicyLayer and add a rule for set_add: 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 set_add? +

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

Can I rate-limit set_add? +

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

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

set_add 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.

KEEP EXPLORING

More on AWS, and thousands of servers like it.

This server

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emit_assumption_set on 0sec →add-tag on Kanban MCP Server →kb_add on Persistent Kb →team_manager_set_sources on Team Manager MCP → The MCP Attack Database →

Guides

Govern customer-ops agents →Argument validation →Scoped token →