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

readOnlyHint=true already declares the safety profile, and the description adds genuinely useful behavior beyond that: 'DTG is assumed unless technique is given' discloses a server-side default, and the underlying endpoint is named. It does not discuss rate limits or auth nuances, but store/token handling is already covered in the schema.

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 compact clauses: the substantive purpose first, then the default-behavior and endpoint note. Nothing is redundant and nothing is padded.

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 does the work by naming what comes back (print areas and per-variant pixel sizes/DPI). Combined with 100% parameter coverage and a read-only annotation, an agent has everything needed to call this 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 description coverage is 100%, so the schema already explains product_id, store_id, technique, and orientation. The description adds meaning for 'technique' by stating the DTG default when it is omitted, which the schema does not say. That is a real increment, though modest.

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?

Specific verb (list) plus concrete resource (print areas/placements and required print-file pixel sizes/DPI per variant), scoped to a catalog product. This clearly distinguishes it from siblings like printful_get_catalog_product (metadata only) and printful_create_mockup_task (which consumes these specs).

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 phrase 'what a design must match before mockups or orders' tells the agent when this is needed — prior to mockup generation or order placement. No explicit alternatives or when-not-to-use statements are given, 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.