create_hlod_layer

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

Annotations already declare readOnly=false, idempotent=true and destructive=false; the description earns credit by explaining what idempotency means concretely ('Idempotent on re-run', with an already_exists return flag) and by disclosing the default streaming-grid settings it applies. It does not cover permission/auth requirements, but the added defaults and re-run semantics go meaningfully beyond the annotations.

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?

Four compact, front-loaded sentences: purpose, idempotency, defaults, layer-type acceptance, then a return shape. No filler, though the inline return object is somewhat list-like rather than prose.

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?

With no output schema, the description compensates by spelling out the return fields (name, package_path, asset_path, layer_type, cell_size, loading_range, created, already_exists, success, saved, message) and the defaults applied. Combined with the annotations' idempotent/destructive profile, an agent has nearly everything needed; only environment preconditions are unstated.

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% and already documents the three params, so the baseline is 3. The description goes further by enumerating the accepted layer_type values ('Instancing', 'MeshApproximate', 'Custom'/'CustomHLODActor') that the schema leaves implicit, plus the cell_size/loading_range defaults the schema never mentions.

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 ('Creates and saves a new UHLODLayer... asset') with the World Partition HLOD qualifier, making it clearly distinct from siblings like get_hlod_layers, remove_hlod_layer, set_hlod_layer_settings, and build_hlod.

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 through idempotency and default values, but never says when to prefer this over alternatives (e.g. build_hlod, create_world_partition_map) or what preconditions (a World Partition map) are needed. Usage is left to inference.

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