Upload one or more files to a file input element. The selector should target an <input type=
AI agents use file_upload to create or update resources in MCP Playwright Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your MCP Playwright Server environment.
This tool creates or modifies data on a web page by uploading files through form inputs. It is reversible (files can be removed/replaced) and does not delete data, making it Write rather than Destructive. The severity is high because an AI agent could upload malicious files, sensitive data, or trigger unintended form submissions.
From the tool's definition Tool name 'file_upload' and description 'Upload one or more files to a file input element' indicates creation/modification of file inputs on web pages.
Attacks that exploit this kind of access
Upload one or more files to a file input element. The selector should target an <input type=. It is categorised as a Write tool in the MCP Playwright Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the MCP Playwright Server MCP server in PolicyLayer and add a rule for 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 Playwright Server. Nothing to install.
file_upload is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the 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 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.
file_upload is provided by the MCP Playwright Server MCP server (j0hanz/playwright-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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