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

The description adds meaningful behavior beyond annotations: imports use zero credits, no subscription or allowance check is performed, upload does not remove backgrounds or fix quality, and animated formats are rejected. It also clarifies the confirmed flag semantics and instructs persisting requestId for retries. This is rich, non-obvious context and does not contradict the readOnly, destructive, or idempotent hints.

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 description is front-loaded with the core purpose and then moves logically through constraints, user-notice requirements, confirmation, transport, and retry behavior. It is dense but justifiable; minor redundancy such as 'Unlimited for every account, including free users' could be tightened without losing information.

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?

The description covers the full invocation path: pre-upload notices, file format and size constraints, confirmation semantics, local-file transport choice, and requestId persistence for retries. Since there is no output schema, success and error response behavior is left implicit, which is the only material gap for a mutating import 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?

With 0% schema coverage, the description compensates well: it maps kind to Object vs Character, explains when confirmed should be true, and advises against using imageBase64 for large local files in favor of the multipart endpoint. projectId and name are not explicitly defined, though they are named in the preferred endpoint and are relatively self-explanatory in context.

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: 'import ONE still PNG or WebP as an Object or Character,' so the purpose is immediately clear. It also communicates key constraints such as still images only and no animated files. It does not explicitly distinguish itself from sibling tools like create_asset or create_character, so it stops short of full sibling differentiation.

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 gives strong usage context: imports are free and unlimited, the user must receive a transparency/quality notice before confirmation, and confirmed should only be set after approval. It also provides transport guidance, preferring multipart POST over large base64 for local files. It does not name an alternative tool or clearly state when a sibling such as create_asset should be chosen instead.

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