download_materials

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

Annotations cover the safety profile (non-readOnly, non-idempotent, non-destructive, openWorld), and the description adds genuinely new behavior: a hard batch cap of 10 and per-item success/failure reporting with a follow-up-call pattern for the remainder. That partial-success semantics is exactly the kind of trait annotations cannot express.

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 tight sentences: the batch operation with its cap comes first, the return semantics second. No filler, no repetition of the tool name.

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 usefully sketches the return shape (per-item success/failure) and the continuation strategy, which is what an agent needs to loop correctly. It stops short of describing what a failure entry contains or whether succeeded items are re-downloadable, but the core call behavior is covered.

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?

There is one parameter and schema description coverage is 0%, so the description carries the burden. It conveys that ids are 'selected materials' and repeats the max-10 limit already encoded as maxItems, but never explains the required id prefix format (ubfile/resource/folder/file:hex) or the mixed-type nature of the array.

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 (download material files) plus the batch scope ('한 번에 최대 10개'), which implicitly distinguishes it from the singular download_material sibling. It never names that sibling outright, so the differentiation is inferred rather than explicit.

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 note that leftovers are handled 'via follow-up calls' tells the agent how to deal with items beyond the 10-item cap, which is useful batching guidance. It does not say when to prefer this tool over download_material or download_material's single-file path, so the alternative routing is left implicit.

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