astronomy_news

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

With zero annotations the description carries the full burden, and it delivers substantive behavioural detail: multi-source fallback order (Sky & Telescope RSS → Universe Today / NASA / Phys.org), the fact that no authentication is required, and the dual return shape (display summary in content, JSON in structuredContent). Freshness, caching, and failure behaviour when all feeds fail are not stated.

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?

Purpose is front-loaded in the first sentence, followed by examples, fallback behaviour, return format, and a compact argument list. Every element is relevant, though the parenthetical asides make it slightly denser than strictly necessary.

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?

For a two-parameter, read-only retrieval tool with no annotations and no output schema, the description covers what is fetched, from where, the fallback chain, the no-auth requirement, the return shape, and both parameters. Only edge behaviours (feed exhaustion, limit bounds handling) remain unaddressed.

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 0% and no enums are declared, so the description must supply all parameter meaning. It documents limit (default 8, maximum 15) and section with the allowed values all/observing/news, which the schema does not encode. It adds clear value but omits e.g. what happens for out-of-range limits.

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 and resource ('天文ニュース・観測ガイドを返す') and enumerates concrete content types (daily news, weekly sky guide, planetary observing highlights), so an agent knows exactly what it retrieves. It does not explicitly distinguish itself from near-neighbours like apod, astronomy_weather, or sky_map_with_satellites, which keeps it short of a 5.

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 example phrasings ('今日の天文ニュース', '今週の星空ガイド', '惑星観測の見どころ') imply when the tool is appropriate, and the section parameter hints at query routing. However, no explicit when-not condition or named alternative sibling is given, so usage is only implied.

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