Upload a local file to Drive in one tool call. Internally chains drive_upload_initiate → direct PUT(s) to B2 → drive_upload_complete. Bytes go straight to B2 — they do NOT pass through the API server (the server is only touched at the start and end of the upload). Files >100 MB use multipart (50 ...
AI agents use drive_file_upload to create or update resources in TrekMail MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your TrekMail MCP Server environment.
This tool uploads files to cloud storage, which is a data modification operation (Write category). While the upload mechanism is sophisticated and handles large files with streaming and multipart uploads, the fundamental action is creating new file data in Drive/B2 storage. It is reversible (files can be deleted later), so it does not meet the Destructive threshold.
From the tool's definition Tool description explicitly states "Upload a local file to Drive" which creates/modifies data. The three-step process (drive_upload_initiate → direct PUT(s) to B2 → drive_upload_complete) confirms write semantics.
Attacks that exploit this kind of access
Upload a local file to Drive in one tool call. Internally chains drive_upload_initiate → direct PUT(s) to B2 → drive_upload_complete. Bytes go straight to B2 — they do NOT pass through the API server (the server is only touched at the start and end of the upload). Files >100 MB use multipart (50 MB chunks); the wrapper streams from disk so memory stays bounded regardless of file size. On any error the wrapper calls drive_upload_abort to release the reservation. It is categorised as a Write tool in the TrekMail MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the TrekMail MCP Server MCP server in PolicyLayer and add a rule for drive_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 TrekMail MCP Server. Nothing to install.
drive_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 drive_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 drive_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.
drive_file_upload is provided by the TrekMail MCP Server MCP server (trekmail/mcp-server). 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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