mat_set_specular

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

Annotations already mark this as destructive (write operation). The description adds the fallback from specular to reflection_color for materials without specular, which is useful and non-obvious. However, it does not disclose any other side effects, such as overwriting existing values or material-type limitations beyond the fallback.

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 very short and front-loaded with the core behavior. The bilingual repetition (Chinese + English) is slightly redundant but the essential information is present in two sentences. No unnecessary fluff.

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 two-parameter setter with no output schema, the description covers the key behavior and the fallback. It does not mention error handling or what happens if the material does not exist, but those are likely implied. Slightly more context about expected side effects would improve it.

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 offers 100% coverage: color is documented as [0-255] array or '#RRGGBB' string, material as name. The description adds no additional parameter-level meaning. Baseline 3 is appropriate.

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: 'Set the specular colour' of a material, and distinguishes this from other material setters by naming the exact property and the fallback for materials without specular. The bilingual text reinforces the same meaning without ambiguity.

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?

No guidance is provided on when to use this tool versus alternatives like mat_set_property or mat_set_diffuse. The description only states the behavior, not the conditions or exclusions. A generic setter could also be used for specular, but no comparison is made.

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