Veo 3.1 MCP Server

upload_image

Upload images to Google Files API for use as reference, first, or last frames in video generation. Returns a reusable file URI for 48 hours.

Instructions

Upload an image to Google Files API for use as reference, first frame, or last frame in video generation. Returns a fileUri that can be reused for 48 hours. This is the most token-efficient way to pass images to video generation.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "source": "<source>"
    },
    "name": "upload_image"
  }
}

Input Schema

Name	Required	Description
`source`	Yes	Source type: 'url' to download from web, 'file_path' for local file
`url`	No	URL to download (if source='url')
`filePath`	No	Local file path (if source='file_path')
`displayName`	No	Optional display name for the uploaded file

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Jan 25, 2026

TDQS

A4.2/5.0

Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively describes key behaviors: the tool returns a 'fileUri that can be reused for 48 hours' (temporal constraint) and is 'the most token-efficient way to pass images' (performance characteristic). However, it doesn't mention authentication requirements, rate limits, or error conditions.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is perfectly concise with three sentences that each serve distinct purposes: stating the core function, describing the return value and constraints, and providing performance context. Every sentence earns its place with no wasted words.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a tool with no annotations and no output schema, the description does well by explaining the return value ('fileUri') and its 48-hour validity. However, it could be more complete by mentioning what happens with invalid inputs, file size limits, or supported image formats given the tool's complexity.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

With 100% schema description coverage, the schema already documents all 4 parameters thoroughly. The description adds no additional parameter information beyond what's in the schema, so it meets the baseline expectation but doesn't provide extra value regarding parameter usage or semantics.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the specific action ('upload an image'), target resource ('Google Files API'), and primary use case ('for use as reference, first frame, or last frame in video generation'). It distinguishes this tool from sibling video generation tools by focusing on image preparation rather than video creation or management.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides clear context about when to use this tool ('for use as reference, first frame, or last frame in video generation') and mentions it's 'the most token-efficient way to pass images to video generation.' However, it doesn't explicitly state when NOT to use it or name specific alternatives among the sibling tools.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Deploy Server