uv_island_operation

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

With no annotations, the description carries the full burden and does well: it discloses that each operation mutates UV data, what each does to the mesh (averaging texel size, relaxing distortion, marking seams, welding points), and numeric bounds that constrain behavior. It stops short of stating defaults or whether edits are undoable/in-place.

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 one-line purpose is front-loaded and the Args block is scannable, with operation semantics grouped inside the enum value rather than scattered. Slightly long, but nearly every line carries information an agent needs; only the missing defaults keep it from being tighter.

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 10-parameter, annotation-free tool, the description covers the prerequisite (object must have a UV map), every parameter, and the effect of every enum value, and an output schema exists so return values need no explanation. Defaults and mutability semantics are the only notable omissions.

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 entirely, and it does: all 10 parameters are documented, including which operation consumes each one (iterations for MINIMIZE_STRETCH, rotation/scale_variation/offset/seed for RANDOMIZE, margin for ARRANGE, threshold for WELD) plus valid ranges. This adds semantics the bare schema cannot provide.

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?

Opens with a specific verb+resource ('Tidy UV islands') and scope ('after unwrapping'), which clearly separates it from uv_unwrap and smart_uv_project. It does not, however, distinguish itself from the sibling pack_uv_islands, which likely overlaps with the ARRANGE 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 phrase 'after unwrapping' implies the correct workflow position, and each operation's parenthetical explains its intent well enough to choose between operations. But there is no explicit when-not guidance or named alternative (e.g., when to use pack_uv_islands instead of ARRANGE), leaving routing to inference.

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