list_geometry_collection_bones

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

Annotations already cover readOnly/idempotent/non-destructive, so the 'Read-only: nothing is generated or saved' line is partly redundant. However, the description adds genuinely new behavioral context not present in the annotations: the two specific error conditions (path fails to load, no geometry data) and the full return shape. The redundancy keeps it out of 5 territory.

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 purpose, then error semantics, then alternatives, then the return shape. Every sentence carries information, though 'Read-only: nothing is generated or saved' partially restates annotations and could be trimmed.

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?

Even without an output schema, the description provides an explicit 'Returns:' block with the full object shape (geometry_collection_path, transform_count, root_count, bones[{name, parent, sim_type}]). Combined with the error and alternative guidance, an agent has everything needed to call and interpret it.

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% and the single parameter's accepted path formats are fully documented in the schema, so the schema carries the load. The description adds only a marginal behavioral note about invalid paths erroring, so the baseline 3 is appropriate.

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 and resource ('List every bone (transform) of a UGeometryCollection asset') and enumerates exactly what each entry contains (name, parent index, simulation type) plus aggregate counts. It explicitly distinguishes itself from get_gc_hierarchy_info and get_geometry_collection_info, so the agent can route 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?

Gives explicit when-to-use-elsewhere routing: 'For levels, root indices and whether proximity is computed use get_gc_hierarchy_info; for damage, mass and source settings use get_geometry_collection_info.' It also states the error conditions (unloadable path, collection without geometry data), so the agent knows both the use case and its failure mode.

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