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

Annotations already declare readOnlyHint=false, openWorldHint=true, idempotentHint=false, and destructiveHint=false. The description adds non-obvious behavioral context beyond that: it creates three pictures and returns the first as soon as it is ready, with the drawing's id. It does not discuss permissions, rate limits, or what happens to failed partial generations, but it meaningfully exceeds annotation coverage.

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 core action and followed by the input forms and return behavior. Every sentence earns its place with no filler.

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 non-trivial image-generation tool with no output schema, the description covers inputs, process, and partial return behavior. It does not explain the output format beyond 'three pictures' or how to retrieve later results via siblings like check_drawing, but it is largely complete for correct invocation.

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 baseline is 3. The description mentions the two input modes (`photo` as a file, `photo_url` as an https link), which aligns with the schema but adds no syntax or format details beyond what the schema already documents.

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 states a specific verb and resource: 'Turns an image into a t-shirt design in the shop’s dot-drawing style.' It also names the two image sources (a person’s photo or an AI-made picture), distinguishing it from generic image tools and from siblings like draw_shirt and print_words.

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 an implied usage example ('put this on a t-shirt') and names source types, but does not explicitly say when to choose this tool over draw_shirt, print_words, or other design tools. No alternatives or exclusions are provided.

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