add_primitive

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the action (adds an object) but does not disclose whether the operation is destructive, whether it requires an open scene, whether it replaces existing objects, or what the return value contains. For a mutation tool with zero annotation coverage, 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 front-loaded with the core purpose, followed by a concise parameter list. Every sentence earns its place, though the parameter list could be slightly more structured. It is appropriately sized for a simple creation 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?

The tool has an output schema, so return values are covered elsewhere. However, with no annotations and 0% schema description coverage, the description should provide more context about behavior, coordinate systems, and valid primitive types. It is adequate for a simple add operation but leaves gaps that an agent might need to resolve.

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 list each parameter with a brief meaning (e.g., 'position: Optional [x, y, z] position'), which adds value beyond the bare schema. However, it does not specify allowed primitive_type values beyond examples, coordinate system conventions, or size interpretation (e.g., radius vs diameter), leaving ambiguity.

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 verb ('Add') and resource ('a primitive object to the Cinema 4D scene'), and the parameter list enumerates the primitive types. It is distinguishable from siblings like create_abstract_shape or create_mograph_cloner, though it doesn't explicitly name a sibling to differentiate from.

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 implies usage: call this when you need to add a primitive object to the scene. It does not explicitly state when to prefer this over create_abstract_shape or other creation tools, nor does it mention any exclusions or prerequisites. The context is clear enough for a basic agent, but there is no explicit routing guidance.

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