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

Annotations only say the call is a non-read-only, non-idempotent, open-world write with no destruction. The description adds substantially more: no payment flows through the tool, printing requires owning or having rights to the art, and there is a concrete rate limit of 30 designs per address per hour. It also discloses what the returned page contains and that errors surface there.

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?

Purpose and output are front-loaded in the first sentence, and the trailing sentences cover fallback behavior, print placement, payment and limits efficiently for a 14-parameter tool. The opening sentence is a dense run-on that could be split, which keeps it just short of 5.

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?

With no output schema and 14 parameters including a nested file object, the description carries significant burden and does explain the return payload (result picture, per-side print dimensions, price with US shipping, problems) and the operating constraints. Minor gaps remain around the developer-oriented parameters (dev, ref, markup_usd) and how duplicate calls are handled.

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 documents all 14 parameters including enums for item, side and front. The description recasts those fields in prose (picture sources, colour, chest-vs-center printing) but adds no format, syntax or default detail the schema lacks, so the baseline 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?

States a specific verb+resource combination: put a picture on an item and return the purchase/preview page, plus the no-picture fallback. It is clear what the tool produces, but it never names or contrasts with siblings such as get_design or check_art, so the agent must infer the distinction.

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 one useful conditional — with no picture it returns the page where the person uploads their own art — which hints at a degenerate usage mode. However there is no explicit statement of when to use this versus get_design, check_art or list_items, and no when-not guidance beyond the print-permission note.

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