upscale_image

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

No annotations are provided, so the description carries the full burden. It only states the operation itself and does not disclose potential side effects, whether the original is modified, authentication requirements, rate limits, or what the return value looks like. This is comparable to the update_drive example rated 2.

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

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

A single, front-loaded sentence with no redundant content. It communicates the essential purpose and resolution options efficiently.

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

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

The tool is relatively simple, but without an output schema or annotations, the description does not explain what the tool returns or any operational constraints beyond the schema's plan note for 4K. It provides enough to invoke but lacks broader context, such as the output format or follow-up steps.

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

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

Schema description coverage is 100%, so the description does not need to add parameter details. It does not go beyond the schema, which already explains media_id, target_resolution, and account. Baseline 3 is appropriate.

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

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

The description states a specific verb ('Upscale'), resource ('an image generated via Google Flow'), and scope ('to high resolution (1K, 2K, 4K)'). It clearly distinguishes from sibling tools like generate_image by focusing on post-generation upscaling.

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

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

The phrase 'generated via Google Flow' clearly indicates the tool is for images already created through that pipeline, providing context on when to use it. However, it does not explicitly mention when not to use it or point to alternatives, so it falls short of a 5.

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