set_unit

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

Annotations already indicate that this is not read-only and not destructive, but the description adds no behavioral context beyond restating the operation. It does not clarify that display units are a UI-level setting, whether the setting persists, or whether it has any side effects on model data.

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 compact, front-loaded with the core purpose, and contains no filler. Each sentence earns its place by either stating the operation or clarifying the accepted unit values.

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 setter with two optional parameters and no output schema, the description is largely complete and includes the essential examples needed to invoke the tool correctly. The only notable gap is the missing usage context, which is already penalized under usage guidelines.

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 0%, but the description explicitly documents both parameters with concrete examples: KN/N/TONF for force and M/MM/CM for length. This compensates for the sparse schema and provides actionable value for choosing valid values.

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 states a specific verb ('Set') and resource ('display units'), and the bilingual wording eliminates ambiguity. It clearly distinguishes from sibling tools like set_render or set_view_angle because it targets units rather than visual rendering or camera state.

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 provides no guidance on when to call this tool, whether it affects the current model globally, or how it relates to any alternative tools. An agent must infer the intended usage context from the tool name alone.

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