ap_material_set_channels

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

No annotations are present, so the description carries the behavioral burden. It discloses partial-update semantics and an API limitation, which is helpful. However, it does not state persistence, effects on existing paint data, or what happens if no active material exists.

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 sentences carry all essential information with no fluff. The action is front-loaded, and the key caveat about omitted channels is included efficiently.

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 simple optional-boolean setter with 100% schema coverage, the description is nearly complete. It covers scope, partial-update behavior, and a relevant API constraint. Minor omissions like active-material prerequisite and return behavior do not seriously impair usability.

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 parameters are already individually documented. The description adds important semantic value by clarifying that omitted channels are left unchanged and that these flags are the material's own paint_* flags, not texture-set channels.

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?

Description uses a specific verb and object: 'Enable or disable which channels the active material paints into.' It clearly distinguishes these from texture-set channels and notes the plugin API has no channel add/remove, preventing confusion with 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 gives clear context: it applies to the active material, uses the material's own paint_* flags, and explicitly excludes texture-set channels. It also states that omitted channels are left alone. It does not name alternative sibling tools by name, but the guidance is sufficient for correct selection.

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