AI agents use upload_image to create or update resources in Portals — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Portals environment.
| Parameter | Type | Required | Description |
|---|---|---|---|
roomId | string | — | Room ID to associate the upload with. Falls back to PORTALS_ROOM_ID env variable if omitted. |
filePath | string | — | Absolute path to an image file. Required unless folderPath is provided. |
folderPath | string | — | Absolute path to a folder containing image files. When provided (and filePath is not), uploads all images in the folder. |
Parameters from the server's own tool schema.
This is a Write operation because it creates and stores data (image files) on a content delivery network. While reversible (files can be deleted later), the tool itself performs creation/persistence without destructive side effects.
From the tool's definition Tool description states 'Upload an image' and 'Returns the asset URL(s)', indicating it creates/persists data (image files) on a CDN without deletion or reversal constraints.
Risk signalsAccepts file system path (filePath)
Attacks that exploit this kind of access
Upload an image (.jpg, .jpeg, .png, .gif) to the Portals CDN. Provide filePath for a single file, or folderPath to upload all images in a directory. Returns the asset URL(s). It is categorised as a Write tool in the Portals MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
upload_image accepts 3 parameters: roomId, filePath, folderPath. The full parameter table on this page comes from the server's own tool schema.
Register the Portals MCP server in PolicyLayer and add a rule for upload_image: 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 Portals. Nothing to install.
upload_image 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 upload_image 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 upload_image. 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.
upload_image is provided by the Portals MCP server (portals-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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