Sketch to render (Sketch AI)

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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false and openWorldHint=true, so the safety profile is covered. The description adds a genuinely useful cost signal ('Costs 1 credit per variation') that no annotation provides, but it says nothing about latency, failure modes, or what the output looks like.

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 tight sentences with zero filler; the core capability is front-loaded and the billing caveat follows. Nothing could be removed 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?

For a 12-parameter, non-idempotent, credit-consuming generation tool with no output schema, the description covers purpose and cost but omits selection guidance against the many design/render siblings and gives no sense of result shape or turnaround. It is minimum viable, not complete.

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% with 12 well-documented parameters (seed, engine, precision, style_reference, etc.), so the schema does all the parameter work. The description contributes no additional parameter meaning, which is the baseline 3 case.

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?

States a specific verb ('turn into') and a clear resource ('photorealistic render') from enumerated input types (sketch, line drawing, floor plan, rough draft). It is clear what the tool produces, but it never distinguishes itself from close siblings like luw_render or luw_interior_design, which could plausibly accept similar inputs.

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 description gives no when-to-use guidance and names no alternatives, despite a crowded sibling set (luw_render, luw_interior_design, luw_exterior_design) that an agent must choose between. The only contextual hint is the credit cost, which is pricing rather than routing advice.

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