Zoom out from an image

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

Annotations already disclose the write/non-idempotent profile (readOnlyHint false, idempotentHint false). The description adds the cost trait ('Costs GPU time'), which is useful behavioral context, but it omits the confirmation requirement and irreversibility that the schema's 'confirm' field carries, so it adds only partial value.

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?

Three short sentences, front-loaded with the effect, followed by the numeric guidance and the use case. No filler and nothing redundant with the title.

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 7-parameter mutation with no output schema, the description covers what the tool does, how the factor behaves, typical use, and the GPU cost, which is close to sufficient. It leaves the confirmation/refusal semantics to the schema, a minor gap given the schema documents them fully.

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 baseline is 3, but the description goes beyond the schema by interpreting the numbers ('200 doubles the frame, 150 is gentler'), giving visual meaning to zoom_factor that the schema's '100 is no change' does not convey.

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 gives a specific verb (pull the camera back) and resource (the existing image, with the new space filled), so the operation is unambiguous. It does not explicitly name or differentiate itself from close siblings like pan_image or upscale_image, which keeps it 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?

It offers one concrete use case (giving a tight shot room for a headline or a logo), which implies when to reach for it, but never states exclusions or names alternatives such as pan_image for shifting rather than expanding the frame. Usage is implied rather than prescribed.

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