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

Annotations declare openWorld and non-idempotent, but the description adds far more: the 3-credit cost with refund-on-failure, the 90-second timeout with a taskKey fallback, the fact that mockup URLs are temporary Printful links, and a 20-mockups-per-hour rate limit. This is exactly the behavioral context annotations cannot convey.

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?

Front-loads the cost, then the action, then the fallback and returns — a sensible ordering with no filler. The trailing promotional link ('Made with AetherWave Studio') is the one sentence that does not earn its place.

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, the description carries the return-value burden and does so: printfileUrl, mockup image URLs and their temporariness, plus the taskKey polling path. Combined with the rate limit and pricing, an agent has everything needed to call and follow up correctly.

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 coverage is 100%, so the schema already documents color, topIn, widthIn, placement, designUrl and garmentId including defaults. The description adds little parameter-level detail beyond noting that a bad garment/colour/placement is not charged; baseline 3 is appropriate when the schema does the heavy lifting.

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 and resource: 'Builds the print file at the garment's own print area and resolution, then renders Printful product mockups.' It is clearly differentiated from its siblings (prepare_design, mockup_status, create_product). The title reinforces this without merely restating the name.

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 routes the agent to concrete alternatives: use the returned printfileUrl with aetherwave_printful_create_product, and poll aetherwave_merch_mockup_status when still rendering after 90s. It also implies the designUrl must come from aetherwave_merch_prepare_design. There is no explicit 'do not use this when...' exclusion, so it stops short of a 5.

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