mat_assign

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

Annotations already indicate destructive/read-write behavior; the description adds meaningful behavioral context: assignment is whole-object only, per-face assignment is not handled, and selection is used when no objects are passed. It does not discuss overwriting existing materials, but the destructive hint covers that implication.

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 bilingual, which lengthens it, but the core action and selection behavior are front-loaded and the per-face limitation is relevant and non-redundant. It could be slightly tighter but is not padded.

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 low-complexity mutation tool with full schema coverage and annotations already conveying destructive/read-write characteristics, the description provides all necessary operational context: target selection, scope limitation, and routing to the correct alternative tool. No return value is needed.

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 input schema already documents both parameters fully (object names with selection fallback, and material name). The description repeats this information without adding new syntax, constraints, or parameter-specific details beyond the schema, so baseline 3 applies.

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 specific action—assign a material to objects—and the optional target behavior (explicit list or current selection). It also explicitly scopes the operation to whole-object assignment, distinguishing it from per-face assignment 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?

It gives explicit usage instructions: pass an object list or omit for the current selection. It also states what the tool does not do (per-face Multi/Sub-Object assignment) and directs users to poly tools for that case, providing clear when-to-use and when-not-to-use guidance.

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