create_vertex_group

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

There are no annotations, so the description carries the full burden of behavioral disclosure. It states the primary action (adding a vertex group) but does not mention side effects, such as whether the operation mutates the existing object, whether it requires the object to be a mesh, or whether it can fail if the group already exists. No details about persistence or undo behavior are given, which is a significant gap 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 a single, efficient sentence. It front-loads the primary purpose ('Add a vertex group to a mesh object') and adds a succinct optional behavior. There is no fluff or repetition, making it easy to parse quickly.

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 tool has 4 parameters (2 required) and no schema descriptions or annotations. The one-sentence description is insufficient to understand the parameter semantics, usage conditions, or expected behavior. It lacks details on how to specify vertices, what the default weight means, or prerequisites like object type. Given the tool's apparent simplicity, a bit more context (e.g., that vertex_indices is a list of integers) would significantly improve completeness.

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 0%, so the description must compensate, but it only hints at 'weight' and 'vertices' without explaining the exact parameters. It does not clarify what 'vertex_indices' should be (list of integers? indices of vertices?), how 'weight' applies to the group or vertices, or the significance of 'group_name' being required. The description adds minimal meaning beyond the bare parameter names.

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 action: 'Add a vertex group to a mesh object', specifying both the verb and the resource. It also mentions the optional assignment of vertices with a weight, which directly relates to the tool's core functionality. This is specific enough to distinguish it from other creation tools in the sibling list.

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 prerequisites (e.g., the object must be a mesh or in edit mode), nor does it reference any sibling tools or conditions that would help an agent decide between this and other creation commands. The agent must infer usage from the name and general context.

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