fracture_geometry_collection

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

Annotations already declare destructive=true and non-idempotent, but the description goes further: it discloses that the asset is saved, enumerates failure modes (empty collection, chance_to_fracture skipping every piece, save failure), and warns that re-fracturing grows the collection geometrically and can stall the editor. This is exactly the extra behavioral context annotations cannot carry.

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?

Front-loaded with the action and scope, and the operational hazard plus the return shape follow in a logical order. The middle sentence defining num_fractures and its failure conditions is long but justified; overall there is no filler.

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?

Although no output schema exists, the description inlines the full return contract (path, num_fractures, transform_count, num_sites, random_seed, success, saved, save_error). Combined with the failure and hazard notes, an agent has everything needed to call and interpret this tool.

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 coverage is 100%, so every parameter is already documented in the schema, establishing a baseline of 3. The description adds only marginal meaning ('num_sites random sites in its bounds') and spends its parameter-adjacent words on num_fractures, which is a return value rather than an input.

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?

States a specific verb plus resource ('Applies Voronoi fracturing to all transforms of a UGeometryCollection asset'), names the key inputs (num_sites sites within the bounds) and the persistence side effect ('then saves it'). An agent can distinguish this from plane_cut_fracture, slice_fracture and cluster_geometry_collection without opening a schema.

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?

Explicitly names an alternative and the condition that selects it ('fracture a fresh one from create_geometry_collection') and warns against the re-fracture case. It does not, however, route among the other fracture siblings (plane_cut_fracture, slice_fracture), so the guidance is strong but not exhaustive.

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