Render two .riv files side by side for visual A/B review

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

With no annotations, the description carries full burden. It discloses labels burned by default, shorter file holds final frame, panel height derived from A and forced onto B, stateMachine precedence over animation, and default background behavior. These are meaningful behavioral traits beyond parameter names.

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 a single well-organized paragraph that front-loads the core purpose, includes concrete examples, and differentiates from alternatives without redundancy. Every sentence contributes information.

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 tool with 14 parameters and no output schema, the description covers key behaviors, defaults, and the output format. It could mention what the tool returns (e.g., path to output file), but overall it provides sufficient context for an agent to decide and invoke correctly.

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 the baseline applies. The description reinforces that artboard/animation/stateMachine are applied to both files, but this is already present in the parameter descriptions. No new semantic value is added beyond what the schema provides.

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 clearly states the tool renders two .riv files side by side into a composite GIF/APNG, with specific verbs and resource types. It also explicitly differentiates from riv_visual_diff, making the purpose unmistakable even among sibling tools.

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 provides explicit when-to-use guidance (e.g., 'rig before/after an edit', 'design variants') and names the alternative riv_visual_diff, explaining why this tool is chosen for side-by-side review rather than pixel diff.

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