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

Beyond the annotations, the description usefully discloses that the operation creates a new design and preserves the original, that subjects remain recognisable with unchanged colours, and that it takes about 45 seconds. It does not cover authentication, quota, or failure behaviour, but it adds meaningful operational context to the non-readOnly, non-idempotent 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?

Three short sentences, front-loaded with the core action and followed by the most important side effects and latency. There is no redundant or filler wording.

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 four-parameter generation tool with no output schema, the description covers the main behavioural concerns: non-destructiveness, preservation of subject identity and colours, and expected latency. It could be slightly more complete by indicating what the new design reference looks like, but it is close to sufficient.

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 the schema already explains design ids, style enum values, optional details, and product formatting. The description does not add parameter-level guidance beyond what the schema provides, so the baseline of 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 and resource ('Redraws a design or the user's own photo in an illustration style') and explicitly states the outcome is a new design while the original is kept. This distinguishes it from mutating siblings such as edit_design or create_design.

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 use case is implied clearly enough: apply an illustration style to an existing design or uploaded photo. However, it does not state when to prefer this over edit_design, create_design, or use_chat_image, nor does it give any exclusions or prerequisites.

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