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

Annotations already declare readOnlyHint and openWorldHint, but the description adds genuinely non-obvious operational facts: it is a public feed requiring no key, costs $0.002 USDC per successful call via x402 on Base/Solana/Arc, and failed calls are not charged. That cost/auth model is exactly the kind of thing an agent cannot get from annotations or schema. It does not mention rate limits or how far back 'latest' reaches.

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?

Front-loaded with what the tool returns and its source, followed by scope, auth, and price — a sensible ordering with no filler. The pricing clause is long but carries decision-relevant information, so it earns its place.

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?

With an output schema present and annotations covering safety, the description only needs to cover source, scope, access, and cost — and it does all four. The remaining gap is the vagueness of 'latest posts only' (no time window), which matters for an agent deciding whether this feed covers the period it needs.

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 100%, so both parameters are already documented, making 3 the baseline. The description adds a small amount (that keyword filtering can also touch categories) but this actually diverges slightly from the schema, which says q matches 'title or summary' only, and it says nothing about the AND-semantics of 'must all appear' or the limit parameter.

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 with unusual precision: 'WordPress.org news posts from the official WordPress news RSS feed', which distinguishes it from the many generic news-search siblings (search_google_news, search_techcrunch_articles, etc.) by source. It also scopes the search ('keyword filter on title/summary/categories') and the recency ('Latest posts only'). It stops short of explicitly naming an alternative tool, which keeps it from 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?

Usage is only implied: an agent can infer this is the tool for WordPress-ecosystem news specifically, and 'Latest posts only' signals it is not for archival research. There is no explicit statement of when to prefer this over search_google_news or search_news_across_the_web, and no when-not guidance.

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