send_keys · Mcp Selenium MCP: Risk & Policy

WHAT IT DOES

What send_keys does on Mcp Selenium

AI agents invoke send_keys to trigger actions in Mcp Selenium. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why send_keys needs a policy

This tool interacts with a live browser via Selenium WebDriver, performing UI actions (clearing a field and typing into it). This constitutes a browser action with real-world side effects depending on what is typed and into what element — e.g., submitting forms, entering credentials, or triggering search queries. The 'Clears the field first' aspect also modifies existing content.

From the tool's definition sends keys to an element, aka typing. Clears the field first.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

send_keys Rate-limited

send_keys stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "send_keys": {
      "limits": [
        {
          "counter": "send_keys_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Mcp Selenium, so you can run agents against it safely.

FAQ

Questions about send_keys

What does the send_keys tool do? +

sends keys to an element, aka typing. Clears the field first. It is categorised as a Execute tool in the Mcp Selenium MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on send_keys? +

Register the Mcp Selenium MCP server in PolicyLayer and add a rule for send_keys: 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 Mcp Selenium. Nothing to install.

What risk level is send_keys? +

send_keys is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit send_keys? +

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

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

send_keys is provided by the Mcp Selenium MCP server (@angiejones/mcp-selenium). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.