ft_setup_face_vertex_groups

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

No annotations are provided, so the description carries full burden. It explains that the tool auto-detects landmarks and creates vertex groups by analyzing topology, and mentions the optional armature hint. However, it does not disclose side effects (e.g., whether existing vertex groups are overwritten), error handling, or performance implications for a mutation tool.

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 concise: two sentences for purpose and one sentence for each parameter. It front-loads the action and uses clear, direct language with no filler.

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?

Given the tool's complexity (auto-detection of facial landmarks) and lack of output schema, the description covers the key regions created and their purpose for ARKit. It could be improved by specifying vertex group naming conventions or that the mesh is modified in place, but it is largely sufficient.

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 0%, but the description provides useful details for both parameters: mesh_name is the face/head mesh, armature_name is optional for bone hints. This adds beyond the bare schema, though the armature hint mechanism is not fully explained.

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 clearly states the verb 'create vertex groups' and the specific resource 'face regions', listing eye loops, mouth loops, brow ridges, cheeks, nose, jaw. It distinguishes from sibling tools like ft_create_arkit_shapes and ft_setup_eye_tracking_full by specifying it sets up prerequisite vertex groups.

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 indicates that these vertex groups are required for ARKit blend shape generation, implying use before ft_create_arkit_shapes. However, it does not explicitly state when not to use it or provide alternatives for already-existing vertex groups.

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