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

Beyond the annotations, the description discloses important behavior: it returns a one-hour upload_page_url, the page accepts up to 5 PNG/JPEG photos, and the user must confirm rights to the photos. It also explains the intended chat-app context and the required follow-up sequence.

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?

The description is front-loaded with the core action and return value, then adds limits and next steps without unnecessary repetition. Every sentence contributes useful operational context.

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?

Given the tool has no input parameters and no output schema, the description provides enough detail: what the tool returns, how long the URL lasts, what the user does on the page, and which tools to call afterward. Nothing essential for correct invocation appears to be 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?

The tool takes zero parameters, so there are no parameter semantics to explain. The description appropriately avoids inventing input details, consistent with the baseline for parameterless tools.

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 clearly states the specific action: generating an upload page URL that lets a user upload reference photos from their own device. It distinguishes the chat-app use case from direct upload paths, but it does not explicitly differentiate itself from nearby siblings such as get_reference_upload_url or upload_reference_image.

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?

It gives clear usage context: use this in chat apps like Claude or ChatGPT that cannot upload files themselves, and it names the follow-up flow of check_reference_upload then create_video(reference_upload_id=...). It does not explicitly state when to prefer the sibling tool get_reference_upload_url instead.

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