blender_material_node_group_create

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

With no annotations, the description carries the full burden. It accurately states the primary effect (creates a reusable node group) and its future usability. However, it does not disclose behavior around naming conflicts, whether this modifies the current material, or what the tool returns after creation, which are relevant for a mutating operation.

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?

Two concise sentences with no filler. The primary action and purpose are front-loaded, and the follow-up sentence provides the key future-use context efficiently.

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 schema already documents parameters and the description explains the reusable nature and eventual instancing, the tool is largely complete. A minor gap is the lack of explicit statement about where the group is stored or whether it becomes active in the current node tree, but this is not severely needed for the primary create action.

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%, with each parameter already documented including socket types and default values. The description adds no additional parameter-level meaning beyond restating that inputs and outputs can be defined, so the baseline score applies.

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 uses a specific verb ('Create') with a clear resource ('reusable shader node group') and states the group's defined inputs/outputs. It also distinguishes this tool from simpler node operations by noting the group can later be instanced via a ShaderNodeGroup node.

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 clearly establishes the intended use case: creating a reusable group for later instantiation in any material. It does not explicitly list exclusions or alternatives, but the context is unambiguous enough for an agent to select this over sibling material_node_add or material_procedural_preset tools.

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