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

Annotations only carry destructiveHint=true, so the description must add behavioral context — and it does: dedup-on-duplicate-URL semantics and asynchronous processing with a polling requirement. It does not clarify what mutation/cleanup the destructiveHint implies, but the async and idempotency behavior is disclosed well beyond the annotation.

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?

Three front-loaded sentences with zero filler: what it does, dedup behavior, then async polling. The endpoint note (POST /files) is compact and useful.

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 compensates by explaining the async follow-up (poll get_file) and duplicate-URL return behavior. It omits what the immediate response looks like and any auth/store-token prerequisites, leaving minor gaps.

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 every parameter (url, type, options, visible, filename, store_id). The description only reinforces the url format/recommendation ('public URL, PNG/JPG'), adding marginal value over the schema baseline.

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 (add) and resource (print file to the File Library) and clarifies the source constraint (public URL, PNG/JPG). It also names the sibling printful_get_file as the polling target, letting an agent separate it from other file/store tools.

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?

Gives clear operational context: files come from a public URL, duplicate URLs return the existing file, and async processing requires polling printful_get_file until status is ok. It stops short of explicitly stating when not to use it or naming alternatives for the add itself, but the workflow guidance is strong.

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