Responds to browser file upload dialogs by selecting and uploading files. Works with file choosers triggered by <input type=
AI agents invoke browser_file_upload to trigger actions in MCP Macaco Playwright. 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.
This tool triggers an external browser operation (file upload) that sends files to remote servers. It performs an action with real-world side effects that depend on what files are uploaded and where — an AI agent could upload sensitive local files to arbitrary web services. This falls under Execute (external operation) with high severity due to potential data exfiltration risks.
From the tool's definition Responds to browser file upload dialogs by selecting and uploading files. Works with file choosers triggered by <input type=
Attacks that exploit this kind of access
Responds to browser file upload dialogs by selecting and uploading files. Works with file choosers triggered by <input type=. It is categorised as a Execute tool in the MCP Macaco Playwright MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the MCP Macaco Playwright MCP server in PolicyLayer and add a rule for browser_file_upload: 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 Macaco Playwright. Nothing to install.
browser_file_upload is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the browser_file_upload 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 browser_file_upload. 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.
browser_file_upload is provided by the MCP Macaco Playwright MCP server (macacoai/mcp-playwright). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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