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

No annotations are provided, so the description carries the full behavioral burden. It usefully discloses that processing happens in the browser, uses more credits than some other workspaces, and that Day Pass does not include this workspace, but it omits key operational details such as how the source video is supplied or where exactly the saved video is stored.

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 purpose is front-loaded, but more than half of the description is generic pricing and credit boilerplate that is not specific to this tool. The double period in 'saved video..' and repeated credit-pack details reduce polish and waste space.

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?

For a zero-parameter transformation tool, the description gives the output format, dimensions, and some cost context, but it never explains how input video is selected or where the output is saved. With no annotations and no output schema, the description should do more to close that gap.

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 has zero parameters, so the baseline score is 4 under the rubric. The description adds useful fixed-output context—1080 × 1920 vertical MP4—but there are no parameters whose semantics need further explanation.

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: resize a video into a 1080 × 1920 vertical MP4 for Reels. It is clearly distinguishable from generic resize tools by the Reels target and exact output dimensions, though it does not explicitly contrast itself with siblings like mio_video_resize_shorts, mio_video_resize_tiktok, or mio_video_resize_square.

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?

There is no explicit guidance on when to choose this tool versus the other resize variants. The text says to review the crop, keep default export settings, and inspect the saved video, but those are workflow steps rather than when-to-use or when-not-to-use criteria.

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