create_soundfield_submix

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

Annotations only cover the safety profile (write, non-destructive, non-open-world), so the description carries the interesting burden and does so: it discloses the disk-write success condition, the no-op re-save behavior for existing assets, the created/already_existed/saved flags, and the default initial state. The only nuance is that this described repeat-call behavior reads as idempotent while idempotentHint is false, but the return payload still differs between first and subsequent calls, so it is a borderline mismatch rather than a contradiction.

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 core semantics are front-loaded in the first two sentences, which is exactly right. The trailing explicit 'Returns:' line partially repeats the return fields already named in sentence two, which is mild redundancy but useful for an agent that only reads the tail.

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 takes on the return-value burden and discharges it, enumerating the returned keys. It covers creation semantics, save semantics, existing-asset behavior, and a follow-up tool, leaving nothing an agent needs to call it correctly 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 the single parameter carries its own format example ("/Game/Audio/MySFSubmix"), so the schema does the heavy lifting. The description references submix_path but adds no path conventions or constraints beyond what the schema states, making the baseline 3 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?

The description names a specific verb and resource (create a USoundfieldSubmix asset at submix_path), states that it is saved, and specifies the resulting state (default encoding format, empty effect chain). The resource type is distinct enough from the sibling create_sound_submix that an agent can disambiguate without opening either 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?

It clearly states the two invocation outcomes (new asset created and written vs. existing asset returned unchanged and not re-saved) and routes the agent to get_soundfield_submix_info for inspection. It stops short of explicitly contrasting against create_sound_submix or add_soundfield_effect_to_submix, so it gives context but no named alternatives.

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