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

With no annotations supplied, the description carries the full burden, and it does disclose the meaningful behavioral difference between modes: crop fills the frame and trims edges (irreversible loss of content), pad fits inside with black bars. It says nothing about re-encoding, output format/location, or processing time, which are the remaining behavioral questions for a media mutation tool.

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?

Two sentences, front-loaded with the action, then the two mutually exclusive sizing paths and the two mode options. Every clause carries information an agent needs to fill the schema; nothing is padding.

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 five-parameter, non-annotated tool with no output schema, the description covers the decisions that matter (which sizing parameter to use, which mode) and explains the visible consequence of each mode. The gaps are the aspect-vs-width/height precedence and any statement about the result, which are moderate rather than crippling given the tool's simplicity.

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 0% and the schema only lists bare titles with defaults, so the description must compensate; it does so well by supplying the concrete accepted aspect strings (9:16, 16:9, 1:1, 4:5, 4:3) and defining both mode values with their visual consequences. It does not clarify precedence when both aspect and explicit width/height are provided, nor does it state that mode defaults to crop, leaving a real ambiguity.

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 first sentence gives a specific verb ('Resize or reframe') and resource ('a video'), and the rest enumerates the exact aspect options and modes, so an agent knows precisely what the tool produces. It does not name or contrast with a sibling such as video_convert, which also transforms video dimensions, so it stops short of a 5.

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?

Usage is implied by the operation itself (change a video's dimensions/framing), and the crop vs pad explanation hints at which output the caller wants. However, there is no explicit when-to-use versus when-not guidance and no mention of when a sibling like video_convert would be the better choice.

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