resize

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

With no annotations, the description carries the full burden and does disclose meaningful behavior: keep_aspect defaults to true, the missing dimension is derived from aspect ratio, and the result is rounded to an even number. However, it is silent on what happens when both dimensions are supplied under keep_aspect, what occurs if neither is given, whether the output file is overwritten, and whether codec/quality is preserved on this write operation.

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 tight sentences, front-loaded with the purpose and followed immediately by the parameter rule that matters most. No filler or restatement of the tool name.

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?

Adequate but not complete for a file-mutating tool with no annotations, no output schema, and 5 parameters at 20% schema coverage. Key gaps remain: the requirement for at least one dimension, the both-dimensions-with-keep_aspect case, and output file/encoding side effects.

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 only 20% (only 'input' has a description), so the description must compensate, and it does: it explains that width and height are individually optional ('and/or'), and defines keep_aspect's effect of deriving and even-rounding the other dimension — meaning the bare schema does not convey. It still adds nothing about 'output' or the minimum-2 constraint.

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'), which is instantly distinguishable from most siblings like trim or extract_audio. It does not explicitly draw the line against crop (spatial cut vs. scale) or convert, so an agent must infer that boundary.

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?

Implies usage by saying 'Give width and/or height', but never states the selection rule versus crop/convert/thumbnail, nor prerequisites such as needing at least one dimension. No when-not guidance at all.

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