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

With no annotations, the description carries the full burden: it discloses aggregation sources, newest-first ordering, and returned fields, which is genuinely useful. It says nothing about rate limits, caching/staleness, how far back the feed goes, or what happens when no articles match, so the behavioral picture is partial.

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?

One dense sentence, front-loaded with the resource and sources, followed by filters and use cases. The field enumeration ('title, link, time, summary and tags') is somewhat redundant given an output schema exists, but it reads easily and has 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 read-only news feed with an output schema covering return values, the description supplies sources, ordering, filters, and intended uses — enough to call it correctly. The residual gap is the undocumented limit/source parameter behavior.

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%, so the description must compensate. It covers only 'q' ('filter by keyword or coin (BTC, ETH, SOL, ETF, Base)'), leaving 'limit' and 'source' unexplained — the agent must infer that source accepts the named publishers and that limit caps results. Partial compensation for two of three undocumented params lands at a marginal 3.

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 resource (crypto news) with named sources (CoinDesk, Cointelegraph, Decrypt, The Block), ordering (newest first), and return fields. It separates itself from sibling market-data tools like crypto_candles or crypto_trending by being explicitly a news aggregator, though it never names an alternative news tool such as read_rss_feed.

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?

Gives concrete use cases: 'explain a price move, brief a trader or monitor a project,' which tells the agent the situations this tool serves. It stops short of exclusions or naming alternatives (e.g., 'use read_rss_feed for arbitrary feeds'), so the routing guidance is one-sided.

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