preview_render

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

With no annotations, the description carries the full burden, and it usefully discloses a non-obvious side effect (a successful render refreshes the coordinate-overlay and rolling GIF vision resources) plus the non-mutation guarantee. However, it says nothing about failure behavior, permissions, size limits beyond 'bounded,' or format probing, so the behavioral picture is partial.

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 with the core action front-loaded and the side-effect detail second. No filler, no redundancy.

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?

An output schema exists, so return values need not be described, and the side-effect note covers the biggest behavioral unknown. Still, for a tool with zero parameter documentation and no annotations, the definition leaves an agent guessing about argument semantics and error/edge behavior.

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 0%, so the description must compensate, and it largely does not. 'Bounded' hints at max_width/max_height but never explains whether the box preserves aspect ratio, whether dimensions are scaled or cropped, or what session_id identifies; the defaults of 1200 are left unexplained.

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 (Render) and a specific artifact (bounded PNG preview), which is more precise than a bare name restatement. It is not fully differentiated from close siblings like vision_capture or export_image, but an agent can tell it produces a preview 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?

No when-to-use guidance is given: nothing says when a preview is preferable to vision_capture, export_image, or export_artwork, and no prerequisites or exclusions are stated. The only usage-adjacent phrase, 'without modifying the artwork,' describes a side effect rather than selection criteria.

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