APIbase

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

With no annotations provided, the description carries the full burden. It successfully discloses the data provider (NewsData.io), scale (180,000+ sources), and return structure (source metadata). However, it omits operational behaviors such as rate limits, pagination, or authentication requirements that would be critical for an external API call.

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 efficient sentences with zero waste: (1) action and filtering, (2) return values, (3) scale and provider. Information is front-loaded with the primary action, and every sentence earns its place by adding distinct value not present in structured fields.

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?

Given the simplicity (3 optional parameters, no nested objects) and absence of an output schema, the description adequately compensates by detailing the return structure. It could be improved by noting that all parameters are optional for full source discovery, but it provides sufficient context for a browse/discovery tool.

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?

The input schema has 100% description coverage with clear examples (e.g., 'us', 'en'). The description confirms the filtering capability ('filter by country, language, and category') but adds no additional semantic detail, format constraints, or usage patterns beyond what the schema already provides, warranting the baseline score.

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?

The description clearly states the tool 'Browse[s] available news sources' with specific filtering capabilities. It distinguishes itself from article-fetching siblings (e.g., news.global.latest) by specifying it returns 'source name, URL, categories, and languages' rather than news content, and identifies the specific resource (NewsData.io) and scale (180,000+ sources).

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?

While the description explains what the tool does, it does not explicitly state when to use this versus alternatives like news.global.latest or currents.news.search. Usage is implied through the explanation of filtering capabilities and return values, but lacks explicit 'when to use' guidance or prerequisites.

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