preview

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

There are no annotations, and the description does not disclose side effects such as file creation (the output PNG) or whether it modifies existing rig data. It simply says 'Render a PNG' without stating if it is read-only or if it overwrites files, leaving behavioral ambiguity.

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 concise and uses a clear list format for parameters, avoiding unnecessary verbosity. It efficiently conveys the tool's purpose and parameter meanings, though the formatting with backticks and angle brackets is slightly cryptic.

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?

The description covers the tool's core function and provides parameter defaults, but lacks a complete picture. It does not mention what the tool returns (e.g., the output path) and omits maxpx, so a user might be uncertain about the full input/output contract.

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?

The description explains three of four parameters (rig_dir, images_dir, out_png) with useful defaults and context, but omits any explanation for maxpx. Since the schema has no parameter descriptions, this partial coverage leaves a gap in understanding the maxpx parameter's meaning or units.

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 explicitly states the tool renders a keyframe-montage PNG of a built rig with specific poses (idle/win/blink/pop), making its primary function clear. It also distinguishes itself from sibling tools like pack_atlas or export_project by focusing on preview generation.

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 no explicit guidance on when to use this tool versus alternatives. It implies it is for previewing a built rig but does not mention prerequisites, sequencing, or scenarios where other tools would be more appropriate.

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