rig-assign_weights

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

With no annotations, the description bears full burden for behavioral disclosure, but it does not mention side effects (e.g., modifies the mesh), constraints (e.g., mode behavior REPLACE/ADD/SUBTRACT), error handling, or prerequisites. The mode parameter is not explained, and there is no indication of whether weights are added or replaced by default.

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 a single concise sentence with no redundant or extraneous wording. It directly states the action, target, and method, making it efficient and well-structured.

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?

The description is minimal and omits critical context: it does not mention prerequisites (e.g., the vertex group must exist on the mesh), what the tool returns (if anything), or how it relates to other rigging operations. Without this, an agent may not know if the tool is appropriate for a given scenario or what side effects to expect.

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?

The schema provides titles like 'Mesh object to edit', 'Blender vertex group assignment mode', 'Vertex group name', 'Weight to assign', and 'Comma-separated vertex indices'. These are reasonably descriptive but lack details (e.g., enum values for mode, weight range). The description does not add any extra meaning beyond the titles, so it does not elevate clarity beyond the schema's basic coverage.

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 'Assign vertex weights to a named vertex group by vertex index' uses a specific verb ('assign') and clearly identifies the resource (vertex weights in a named vertex group) and the targeting method (by vertex index). It distinguishes from sibling tools like rig-set_bone_transform (bone transforms) and rig-parent_with_auto_weights (automatic parenting), making the purpose unambiguous.

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?

No guidance is provided on when to use this tool versus alternatives. It does not mention when manual weight assignment is appropriate instead of automatic methods, or any prerequisites (e.g., vertex group must exist). Lacks explicit when/when-not conditions.

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