copy_mesh_uv_channel

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

Goes well beyond the annotations: channel count only grows, intermediate channels are added with no UVs, validation happens before mutation (atomicity), a same-channel call succeeds with copied=false plus a note, and there is no undo entry and nothing is saved. This is exactly the behavioral context the boolean hints cannot convey.

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 purpose, then conditions, then the return shape; every sentence carries information. The prose is dense and slightly run-on (nested clauses about before/after state), but nothing is wasted.

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?

There is no output schema, so the inline Returns block is necessary and it fully documents the response fields, including that actor_name is the component name rather than the actor label and when note is populated. Combined with the mutation and persistence caveats, an agent has everything needed to call this correctly.

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 already 100%, so the baseline is 3, but the description adds real meaning beyond the schema: the source channel must already exist or the call errors, and dest_channel is created on demand up to the 0-7 limit. That clarifies the two channel indices rather than merely restating them.

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 first sentence gives a specific verb and resource: 'Copy UV data from one UV channel to another on the same mesh.' It is unambiguous and clearly distinct from the read/clear UV siblings, though it never names a sibling tool or scope where copy vs. set_num_uv_channels / set_triangle_uvs might overlap.

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?

Preconditions and failure modes are spelled out: a missing source_channel or a dest_channel >= 8 is an error checked before any change, and identical channels are a successful no-op. That effectively tells the agent when the call is legal and when it isn't, but it never routes the agent to an alternative tool for the cases it rejects.

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