create_subtitles_asset

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

Annotations already declare readOnly=false, destructive=false, and idempotent=true, but the description adds real behavioral context: it explains the package creation under /Game via NewObject and explicitly confirms idempotent behavior ('returns it with already_existed: true'). Because there is no output schema, disclosing the return shape is genuinely additive.

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?

Three sentences, front-loaded with the core creation action and then the idempotency/return details. Given the absence of an output schema, the explicit return field list earns its place rather than being waste.

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?

For a two-parameter creation tool with full schema coverage and no output schema, the description covers purpose, idempotency, and the return shape, with annotations covering the safety profile. Only minor gaps remain (no stated prerequisites or side effects on existing cues within a reused asset).

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%, so both 'name' and 'package_path' are already documented. The description lightly reinforces the destination folder ('under /Game'), which maps to the package_path default, but adds no syntax or format detail beyond the schema. Baseline 3 applies.

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 gives a specific verb+resource ('Creates a USubtitleAssetUserData asset') and clarifies it is the UE 5.8 subtitle authoring asset, which is unambiguous. It does not reference sibling tools like remove_subtitles_asset or add_subtitle_cue, so it lacks sibling differentiation, but the action itself is crystal clear.

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?

There is no guidance about when to use this tool versus alternatives (e.g., create a cue vs. the asset, or how it relates to remove_subtitles_asset). The idempotency note implies repeated calls are safe, but no explicit when/when-not conditions are stated.

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