stream_add

THE RISK

Low Risk

Why stream_add needs a policy

With no description available, I can only infer from the tool name. 'stream_add' could mean adding data to a stream (Write), adding a stream resource (Write), or something else entirely. Given sibling tools suggest AWS context with data operations, this likely involves writing/appending to a stream resource, but confidence is very low.

From the tool's definition Tool name is 'stream_add' but description is empty or uninformative.

Documented attack patterns abuse exactly the kind of access stream_add gives an agent:

POLICY

How to control stream_add

PolicyLayer is an MCP gateway — it sits between your AI agents and AWS, and nothing reaches the server without passing your rules. This is the rule we recommend for stream_add:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "stream_add": {
      "limits": [
        {
          "counter": "stream_add_rate",
          "window": "minute",
          "max": 60,
          "scope": "grant"
        }
      ]
    }
  }
}

stream_add gets a rate cap, and everything else on the server is denied unless you say otherwise.

Create a free account and register AWS — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

SET A RULE FOR THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More AWS tools

Destructive bulk_delete_by_criteria bulk_delete_by_criteria Destructive cache_delete Delete a value from the cache. Args: key: The key to delete Returns: Destructive cache_delete_many Delete multiple values from the cache. Args: keys: List of keys to delete Destructive cache_delete_multi Delete multiple values from the cache (alias for delete_many). Args: keys: Li Destructive delete Delete a Valkey key. Args: key (str): The key to delete. Returns: Destructive delete_access_key delete_access_key Destructive delete_datastore Delete a data store from AWS HealthImaging. Destructive delete_group delete_group

All 300 AWS tools →

Other tools on other servers

Android Forensics ADB MCP Server generate_app_analysis_report Ethereum Tools add Math MCP Server complex_analysis_suite Crypto_MCP aes_encrypt

Go deeper

Roll out MCP under one policy → Per-person scoped tokens, one central policy, and full audit across every server your team connects.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Tool risk categories → How PolicyLayer classifies MCP tools by what they can do.
MCP tool → What an MCP tool is and how clients discover and call it.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →
PolicyLayer vs alternatives → How deterministic, per-call MCP policy compares with gateways, identity layers, and authorisation platforms.

FAQ

Questions about stream_add

What does the stream_add tool do? +

stream_add. It is categorised as a Other tool in the AWS MCP Server, which means it performs auxiliary operations.

How do I enforce a policy on stream_add? +

Register the AWS MCP server in PolicyLayer and add a rule for stream_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 stream_add? +

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

Can I rate-limit stream_add? +

Yes. Add a rate_limit block to the stream_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 stream_add completely? +

Set action: deny in the PolicyLayer policy for stream_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 stream_add? +

stream_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.

Enforce policy on every AWS tool call.

Start from AWS, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →