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

Annotations already cover the safety profile (readOnly, openWorld, non-idempotent), so the bar is lower, yet the description adds genuinely useful behavioral facts: results can be up to an hour stale due to caching, and the per-call price/payment mechanism ($0.002 USDC via x402 or credits, free trial). It does not describe rate limits or failure modes, hence not a 5.

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 a clear one-line summary, but contains redundancy and marketing filler ('★ One of our best tools', 'Cheapest search' restating essentially the same pitch twice) and repeats the price/credit detail. Roughly half the sentences could be trimmed without losing information.

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?

An output schema exists, so return values needn't be explained. The description covers sources, freshness, cost, and payment, which is most of what an agent needs; the only meaningful gap is the absence of a pointer to the sibling search variants for differentiation.

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 100% for both parameters (q and limit), so the schema already documents them fully. The description adds no syntax, format, or default guidance beyond the schema, so the baseline 3 applies.

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 (search) and enumerates the resources searched (Wikipedia, Hacker News, DuckDuckGo, Stack Overflow) plus what a result contains (titles, links, snippets, dates). This is clear and concrete, though it never explicitly differentiates itself from the sibling tools named 'search' and 'search-answer', which an agent must disambiguate on its own.

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?

Provides soft context ('good for facts, tech topics and programming questions') that implies when to use it, but gives no when-not-to-use guidance and never names the obvious alternatives (search, search-answer) that also perform web search. Usage is implied rather than routed.

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