scale

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

With no annotations, the description carries the full burden; it does disclose that the video is re-encoded, which hints at quality loss and processing cost, and the schema covers output path defaults and overwrite. It does not say whether the source file is left untouched, what the output format is, or whether dimensions must be even for video codecs.

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 and followed by the one decision rule that matters. Nothing is wasted and nothing needs re-reading.

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 transformation with no output schema and no annotations, the description plus the fully-described schema covers the essentials of choosing and calling it. The only real gap is that it does not establish where this sits relative to the other video-transformation siblings.

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 every parameter is already documented, and the schema descriptions themselves state the aspect-ratio derivation rule. The description restates that rule at the tool level but adds no new semantics such as rounding, minimum size, or interaction with output/overwrite.

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?

States a specific verb and resource ('Resize a video') plus the mechanism ('re-encode'), which is enough to distinguish it from a pure metadata edit. However it never contrasts itself with nearby siblings like crop, reframe, or zoom, so the agent must infer the boundary itself.

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?

'Provide one side to keep the aspect ratio, or both to set an exact size' explains how to drive the parameters, which implies usage but does not state when this tool is the right choice over crop/reframe/compress. No exclusions or preconditions are given.

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