rhino_block_define

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

The description goes beyond the sparse annotations by explicitly stating that bridge mode replaces the source objects with a single instance at the base point, which is a critical mutation side effect. It also discloses the two operation modes, though it stops short of noting irreversibility, undo behavior, or name-conflict handling.

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 one-sentence summary is front-loaded and the second sentence adds behavioral detail without repeating the schema. The standalone/bridge explanation is useful despite the implementation-specific 'rhino3dm.InstanceDefinitionGeometry' reference, which is somewhat extraneous.

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 description gives enough to attempt a call, but it does not state prerequisites (e.g., whether object_ids must exist in the document), what happens on duplicate names, or when standalone vs bridge mode is chosen. The presence of an output schema lessens the need to document return values, but the operational context remains somewhat incomplete.

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?

The description maps several schema parameters to its prose ('list of objects' -> object_ids, 'under name' -> name, 'base point' -> base_point, 'replace_objects=True'). However, it does not add meaning for doc_id or the description parameter, and with the reported 0% schema description coverage at the top level, it only partially compensates.

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 'Create a block definition from a list of objects', using a specific verb and resource that distinguishes it from sibling tools like rhino_block_insert or rhino_block_explode. The standalone/bridge mode detail further clarifies what the operation accomplishes.

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 the use case (defining a block from selected object IDs) and contrasts standalone vs bridge modes, but it never explicitly says when to choose this tool over alternatives or when not to use it. No sibling alternatives are mentioned, so the agent must infer routing from the name.

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