Sketch to render (Sketch AI)

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

Annotations already declare readOnlyHint=false, openWorldHint=true, idempotentHint=false, so the mutation/non-reproducible profile is covered. The description adds a genuinely useful billing fact ('costs 1 credit per variation'), but omits other behavioral traits such as whether the job is asynchronous and must be polled via luw_get_result, or any auth/quota requirements.

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 with no filler and the purpose front-loaded ahead of the cost note. The 'Luw.ai Sketch AI:' lead-in is mild branding repetition of the title rather than information, otherwise fully efficient.

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 generation tool with no output schema and no result-retrieval documentation, the description is thin on the workflow side. Given the crowded sibling set (luw_render, luw_interior_design, luw_generate_image, luw_get_result), the absence of any disambiguation leaves an agent guessing which tool to invoke.

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 12 parameters (including enum meanings, precision scale, styles case-sensitivity, and style_reference semantics) are already documented. The description only echoes the per-variation billing that the schema also states, adding no new parameter meaning beyond the baseline.

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 transformation (sketch/line drawing/floor-plan perspective/rough draft → photorealistic render), which is concrete and distinguishes the input type. It does not, however, differentiate itself from close siblings like luw_render or luw_generate_image, so the agent must infer the boundary.

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 through the input type: an agent can infer 'use this when the source is a hand sketch.' There is no explicit when-to-use, when-not-to-use, or named alternative (luw_render, luw_interior_design, luw_exterior_design), so routing among the 24 siblings is left to inference.

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