set_triangle_uvs

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

Annotations declare destructive=true and idempotent=true, and the description exceeds that bar by disclosing the side effect (the triangle becomes an isolated UV island, fresh UV elements allocated per call) plus the exact conditions under which validity returns false. This is exactly the kind of consequence detail an agent needs before mutating UVs.

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 action and the island side effect before the ID semantics and validity rules. The trailing 'Returns:' line is useful given there is no output schema, though the prose is dense enough that a slight trim would help.

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 mutation tool with no output schema, the description covers input semantics (0-based IDs), side effects (isolated island), failure criteria, and enumerates the return payload. An agent has everything needed to call and interpret 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?

Schema description coverage is 100%, so the baseline is 3. The description reiterates the 0-based triangle indexing that the schema already documents and adds no syntax or format detail beyond it, so it does not meaningfully beat 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 and resource ('Set the 3 UV corners of a single triangle in one UV channel') with an explicit scope (single triangle, one channel). It distinguishes itself from repack/regeneration siblings by framing itself as the granular-edit path, so an agent can pick it over repack_mesh_uvs or auto_generate_mesh_uvs.

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?

Gives clear usage context ('Use this for granular UV edits without a full repack / regeneration'), which orients the agent toward the narrow-edit scenario. It stops short of naming a specific alternative tool or stating when-not to use it, which keeps it below a 5.

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