Resize a static ad for other placements

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

The description discloses meaningful behavioral details beyond the annotations: it reads the ad's text first and charges 3 credits, performs one image edit per canvas, and is priced before it runs. It also clarifies that the output is a native recomposition rather than a crop. None of this contradicts the annotations, so the description adds substantial transparency.

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 description is compact but information-dense, with every sentence earning its place: purpose and constraints, parameter usage, operational behavior and cost, and the video alternative. The phrasing 'word for word' and 'rather than cropped' packs crucial differentiation into short clauses without 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 two-parameter tool with no output schema, the description is complete: it covers what the tool does, how to invoke it, valid parameter values, defaults, cost, execution timing, and the main alternative. No information necessary for selecting and correctly invoking the tool is missing.

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?

Even though the schema already documents both parameters, the description adds significant semantic value: it names the valid aspect ratios, states the defaults (1:1, 4:5, 9:16), and reveals the important rule that the ad's own ratio is skipped. It also clarifies that 'image' must be a finished static ad and that copy must survive verbatim.

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 uses a specific verb and resource: 'Re-lay out ONE finished static ad for other placements.' It further defines the exact scope of the operation by stating that the same copy, product, logo, and style must be preserved and recomposed natively rather than cropped. This clearly distinguishes resize_ad from related sibling tools such as reframe_video, remix_static, or edit_image.

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?

The description explicitly scopes when the tool is appropriate: it is for ONE finished static ad destined for other placements. It also provides a clear exclusion and alternative: 'For VIDEO use reframe_video.' This gives the agent a concrete when-not condition and a named sibling to route to instead.

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