pack_uv

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

With no annotations, the description carries the full burden. It discloses auto-grows texture preserving paint and that all cubes get their own region. However, it does not explain what happens to existing UVs or specify any destructive behavior (e.g., overwriting UVs).

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 sentences, each earning its place: action, required context, and auto-resize behavior. No unnecessary words, front-loaded with the key purpose.

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?

Given the tool's complexity (3 simple parameters, no output schema), the description is fairly complete. It explains why the tool is needed and when to re-run. A minor gap is lack of detail on how padding affects layout or what 'all' means for cubes parameter.

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 description coverage is 100%, so the schema already documents the parameters. The description adds minimal extra meaning beyond the schema; for example, it does not clarify the format of cube names or the effect of padding.

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 action ('Shelf-pack the box UVs') and the specific resource ('box UVs for a box_uv model'). It distinguishes itself from siblings like set_cube_uv by indicating it packs all cubes into their own region, which is a distinct operation.

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 says 'REQUIRED before texturing' and 'Re-run after adding or resizing cubes', providing clear when-to-use guidance. However, it does not mention when not to use or compare with alternative tools like set_cube_uv for individual adjustments.

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