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

With no annotations, the description carries the full burden, and it does disclose two valuable traits: the $8/1,000-row cost on the Apify account and that query/language filtering happens client-side after billing (i.e., filtering does not reduce cost). It remains silent on auth requirements, return shape, and how sources/sourceTypes are resolved.

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, front-loaded with the purpose and immediately followed by the cost implication. No filler, though it is quite terse for a five-parameter tool.

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?

No output schema and low schema coverage mean the description should do more. Billing and filtering semantics are covered, but the meaning and valid values of sources (vs the enum-constrained sourceTypes) are never addressed.

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 only 20% (just maxItems), so the description must compensate. It clarifies that query and language are applied locally post-billing, which is real semantic value, but sources and sourceTypes are left entirely undocumented in both schema and description.

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 ('Fetch') and resource ('China news'), which is distinct from the sibling resources (hot lists, deletions) without needing to name them. No explicit sibling differentiation, but the resource itself is unambiguous.

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?

No indication of when to use this versus get_hot_lists or get_deletions, and no prerequisites or exclusions. The only contextual guidance is billing mechanics, which is not a use-case signal.

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