blender_annotation_add

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

No annotations are provided, so the description carries the behavioral disclosure burden. It does state that the tool adds to the scene as a grease pencil annotation layer, implying a non-destructive additive operation. However, it does not disclose whether strokes are appended to existing layers, whether they can be cleared later, or any side effects beyond the layer creation.

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 sentences with no filler: the first front-loads the action and resource, the second provides relevant use cases. Every sentence earns its place, and the description is appropriately sized for a simple tool.

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 additive tool with four fully documented parameters and no output schema, the description is largely complete. It explains what the tool does and when to use it. The main gap is the lack of explicit guidance on choosing among nearby annotation-related siblings, which prevents a perfect score.

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%, so the schema already documents all parameters. The description adds little beyond '3D annotation strokes' and 'grease pencil annotation layer,' which slightly enrich the meaning of points and layer_name. Per the baseline rule, this warrants a 3.

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 states a specific verb and resource: 'Add 3D annotation strokes to the scene as a grease pencil annotation layer.' This clearly conveys what the tool does and implicitly distinguishes it from annotation_text and annotation_dimension siblings by focusing on strokes. However, it does not explicitly distinguish itself from the similarly named grease_pencil_markup tool, so it stops short of perfect sibling differentiation.

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 gives clear usage context: 'marking up geometry, drawing guides, or highlighting areas of interest.' This tells an agent when this tool is appropriate. It does not mention alternatives or exclusions, such as using annotation_text for text labels or annotation_clear for removal, so it lacks explicit when-not-to-use guidance.

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