Upload an image

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

The description goes well beyond annotations by disclosing the URL's 24-hour expiration, the 20 uploads per day per account quota, the zero credit cost, and the rendering warning when aspect_ratio is omitted. These are non-obvious behaviors an agent needs to handle correctly.

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?

Each sentence carries a distinct, necessary fact: purpose, URL expiration, when to use, aspect_ratio consequence, zero cost, and daily quota. There is no filler, and the flow from action to constraints to caveats is logical and efficient.

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?

With one simple parameter and no output schema, the description covers everything required for correct invocation: the returned https URL, expiration, daily limit, downstream usage, and a formatting caveat. No significant behavioral information is missing.

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 coverage is 100%, so the schema already defines `path` as absolute/relative to a PNG or JPEG. The description adds value beyond that by emphasizing 'LOCAL' and introducing the 'up to 10 MB' size cap, which an agent cannot infer from the schema alone.

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 and resource: 'Upload a LOCAL image file' and the intended outcome, 'get an https url to pass as `image` to quote_ugc / make_ugc.' It clearly distinguishes itself from sibling tools, none of which handle image uploads, and additionally specifies accepted formats (PNG or JPEG) and size (up to 10 MB).

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 description explicitly says when to use it: 'Use this whenever the user points at a file on disk — `image` itself accepts only public https urls.' It also provides workflow context by telling the agent to set `aspect_ratio` after uploading affects rendering, which reinforces when this tool is the required step.

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