Modify curve geometry by adding, removing, or moving control points in Blender. Specify the curve object and action to adjust its shape precisely.
Add or remove curve control points.
Args: curve_name: Curve object name. action: add, remove, or move. points: [x, y, z] for add/move actions. index: Point index for remove/move (-1 = last).
| Name | Required | Description | Default |
|---|---|---|---|
| index | No | ||
| action | No | add | |
| points | No | ||
| curve_name | Yes |
Changes observed during successful MCP inspections.
v3.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It states the operation types but does not disclose consequences such as whether the modification is in-place, what happens on invalid indices, whether the curve must already exist, or any error behavior. For a mutation tool, this is a significant gap.
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 compact and efficiently front-loaded with the purpose. The parameter list is a clear, structured bulleted list with no wasted text. Every sentence earns its place.
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 simple curve-point editor, the description covers the core operations and parameter meanings. However, it lacks context about the coordinate system (e.g., object vs. world space), the 'move' action's exact behavior (does it set absolute position or offset?), and error handling on invalid indices or missing curves. These gaps could lead to misinvocation.
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. It does so by explaining each parameter: action lists allowed values, points is defined as [x, y, z] for add/move, and index has the special value -1 for last point. This adds meaning beyond the raw schema types, though it leaves some combinations (e.g., remove not needing points) implied rather than explicit.
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 opens with a clear verb-resource pair: 'Add or remove curve control points,' and the parameter list details the add/remove/move actions. This unambiguously distinguishes it from mesh editing siblings (edit_mesh_vertices, edit_mesh_edges) by specifying 'curve.'
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 tool explicitly targets curve control points, and the action parameter ('add, remove, or move') implies the primary use cases. It does not name alternative tools or when-not-to-use scenarios, but the resource ('curve') is distinct enough that an agent would know when to apply it versus mesh or object editing tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.