set_static_mesh_lightmap

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

Annotations already declare idempotentHint=true, destructiveHint=true, and readOnlyHint=false, covering the safety profile well. The description adds that lightmap data is changed and no rebuild occurs, but does not state permission needs, reversibility, or save semantics beyond the return field 'saved'.

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 short, front-loaded sentences: the action first, then the return shape. No filler or redundancy.

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?

Covers the action, the no-rebuild constraint, and lists the return fields, which partially compensates for the absent output schema. However, it does not explain save behavior or the destructive implications that the annotations flag.

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 100%, so the schema already documents all three parameters including their types and optionality. The description adds only the 'and/or' semantics, which is marginal value over the schema.

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?

States a specific verb+resource (set lightmap resolution/coordinate index on a static mesh) and distinguishes from the sibling get_static_mesh_lightmap by being the setter. The parenthetical '(no rebuild)' further narrows the 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 '(no rebuild)' note implies a distinction from operations that would trigger a rebuild, but no explicit when/when-not guidance or alternatives are named. Usage context is implied rather than spelled out.

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