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 does disclose the payment model (5 free trial calls per signed wallet), which is genuinely useful context, but says nothing about output format (e.g. "16:9" vs 1.777), precision, or handling of zero/invalid dimensions.

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?

It is short and front-loaded, but the title is duplicated as the body text ("Aspect Ratio: Aspect ratio calculation"), wasting the only substantive sentence. The pricing note is bolted on without structure.

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?

With no annotations, no output schema, and zero parameter documentation, the description leaves too much unstated for another agent to call it confidently. It should at minimum describe the inputs and the returned ratio representation.

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 description adds nothing about the two parameters. It does not clarify whether width/height are pixel values, ratio components, or numeric strings, which is exactly the ambiguity the string type creates.

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 reads "Aspect Ratio: Aspect ratio calculation," which essentially restates the tool name rather than adding specificity. It never states that it takes width and height and returns a ratio, nor does it distinguish this from the near-identical sibling x402-aspect-ratio-calc. This is tautological rather than clarifying.

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 when-to-use guidance, no mention of the sibling x402-aspect-ratio-calc that appears to do the same thing, and no indication of what input format is expected. The only extra sentence concerns pricing, not usage selection.

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