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

With no annotations, the description carries the full burden and does well: it discloses that it is free, needs no key, returns top Wikipedia matches with summaries, and limits HN stories to the last 30 days. It does not explicitly state read-only behavior or result limits beyond 'top,' but 'lookup' strongly implies a safe read operation.

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?

A single compact sentence with the most important qualifiers front-loaded: FREE, no key, sources, and recency. Every element earns its place with no filler.

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 simple one-parameter lookup tool with no annotations or output schema, the description is mostly complete: it covers pricing, auth, data sources, recency, and return content. It could be fuller by specifying expected result counts or clarifying the exact output shape, but it is sufficient for correct invocation.

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 0% and there is one required parameter. The description adds some meaning by saying the query is 'for a topic,' which tells the agent what to supply, but it does not provide format examples or clarify whether the topic should be a keyword, phrase, or entity name.

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 gives a specific verb and resource: quick news and facts lookup for a topic, using Wikipedia and Hacker News. It distinguishes itself somewhat through 'quick' and named sources, but does not explicitly contrast with siblings like news_search or facts_search.

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?

It implies usage through 'quick' and 'top matches,' suggesting a shallow lookup versus deeper searches, but it never states when to use this instead of news_search, facts_search, or news_briefing. The 30-day recency window is useful context, though not a usage rule.

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