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

The annotations already cover the safety profile (readOnly=false, destructive=false, idempotent=false, openWorld=false), and the description adds genuinely new context: the generation model, automatic product fitting, transparent background for clothing, and a ~45-second latency the agent can plan around. It stops short of saying whether repeats create duplicate designs or whether credits are consumed.

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?

Two sentences, front-loaded with the action, then the differentiating behavior, then the latency hint. Nothing is redundant and every clause carries 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?

As a non-read-only, non-idempotent creation tool with no output schema, the agent is left not knowing what comes back (a design ID, URL, or preview) or how to reference the result in later edit_design/place_order calls. The 45-second timing is helpful, but the return-value gap is material for a create 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?

Schema description coverage is 100%, so all three parameters (text, product, description) are already documented in the schema. The description only echoes 'product' fitting and the visual attributes that belong to the description field, adding no syntax, format, or constraint detail beyond the schema. Baseline 3 is 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 gives a specific verb and resource ('Create a new design') plus the mechanism ('our image model') and a key output trait ('fitted to the product, aspect ratio, transparent background for clothing'). It clearly implies a new design versus edit_design/restyle_design, but never names the siblings, so differentiation is inferred rather than stated.

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?

Usage is only implied: 'Create a NEW design' hints that editing existing designs belongs to edit_design or restyle_design, and the mention of text/pose/colour suggests when a rich description is needed. There is no explicit statement of when to prefer this over use_chat_image or restyle_design, and no prerequisites or exclusions.

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