set_num_uv_channels

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

Goes well beyond the annotations: discloses that added channels start without UVs, channels removed from num_uv_channels upward lose their UV data, the 8-channel engine cap produces an error, the read-back mismatch failure condition, no undo entry and nothing saved, and that actor_name is the component name rather than the actor label. This is exactly the destructive/idempotent context an agent needs.

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?

Front-loaded with the core effect and packed with genuinely useful constraints, but there is some redundancy, e.g. the actor_name 'not the actor label' caveat and the read-back behavior are each stated twice.

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?

With no output schema, the description fully covers the return shape and field semantics, plus error conditions, side effects, and sibling routing. An agent has everything needed to invoke and interpret the call.

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 the baseline is 3, but the description adds real meaning: actor_name is the dynamic mesh component's name, not the actor label, and num_uv_channels is the value read back after the call. These distinctions are not in the schema text.

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?

Specifies verb (Set), resource (number of UV channels), and precise target (live dynamic mesh of a DynamicMeshActor in the editor world). An agent can distinguish it from copy_mesh_uv_channel, generate_mesh_uvs, and clear_uv_channel without opening schemas.

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?

Explicitly routes the agent: fill a channel with copy_mesh_uv_channel or generate_mesh_uvs, and notes clear_uv_channel operates on static mesh assets instead. It also states that calling with the current count is a no-op, so the agent knows when not to bother.

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