blender_create_primitive

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

Annotations already indicate this is a mutable operation (readOnlyHint=false). The description adds that it returns JSON about the new object and gives an example. It doesn't disclose potential edge cases like name collisions or unit conventions, but it's not misleading. With annotations reducing the burden, this is adequate.

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 compact docstring with a purpose line, args, return, and example. It is front-loaded with the action and uses no filler. Every part 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?

This is a simple creation tool with an output schema. The description tells agents what it creates and what to expect in return. It doesn't mention all supported primitive types (though the schema enum does) or coordinate conventions, but for typical usage it's sufficient. Given the low complexity, a 4 is appropriate.

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?

Although the schema has detailed descriptions, the context signal says schema coverage is 0%, meaning the description must compensate. The description explicitly lists the key fields (primitive_type, name, location, size) and provides a concrete example, making the parameter semantics clear. It doesn't repeat default values, but the schema covers those.

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 the specific verb 'Create' with the resource 'primitive mesh' and enumerates examples (cube, sphere, cylinder). It is immediately clear that this tool is for adding meshes, distinguishing it from transform/delete and other sibling operations.

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?

It clearly states the tool's purpose and provides an example invocation. It doesn't explicitly state when not to use it or mention alternatives, but the context is so straightforward that an agent can infer usage. No competing create-primitive sibling exists.

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