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

With no annotations present, the description carries the behavioral disclosure burden and does so well: it reveals asynchronous rendering, immediate job-id return, non-attachment to products, no storefront-sync surface, and the need to carry the artwork URL onward. It stops short of explicitly stating whether the saved design itself is mutated or that generation consumes credits, but the schema's npub field hints at billing and the overall transparency is strong.

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?

The description is organized into three short, purposeful paragraphs: core action, limitations, and async flow. Every sentence adds information, and the key constraints are front-loaded. It is slightly verbose in phrasing but not wasteful given the behavioral nuances it must convey.

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?

The description covers the essential non-schema context: async job handling, status polling, non-product attachment, and the requirement of an existing saved design. An output schema exists, so return-value details are not needed here. The main omissions are whether the source design remains unchanged and the explicit billing/credit consequence, but these are partially inferable from schema fields and the 'free' status-tool contrast.

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 80%, so the schema already documents product_id, fields, client_req_id, and npub. The description paraphrases the fields placeholder mechanism and saved-design requirement but adds little parameter-level meaning beyond the schema. The dpop_token parameter remains undocumented in both schema and description, so no extra semantic value is contributed there.

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 opens with a specific verb and resource: 'Generate packaging artwork from one of your saved Design Studio designs.' It further clarifies the mechanism (rewrites named text and image placeholders) and explicitly contrasts itself with from-scratch authoring and product attachment, making its purpose unmistakable among the many roastify siblings.

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 clear context: use this when you have a saved design you authored and want personalized packaging artwork. It also states when not to use it (cannot author from scratch, artwork is not attached to a product) and explicitly directs the agent to roastify_artwork_status for checking the job. However, it does not name an alternative tool for from-scratch authoring or product creation, leaving some routing implicit.

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