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

Annotations only cover readOnlyHint and openWorldHint, yet the description adds substantial operational context beyond them: it returns only the first page with no pagination, omits ads and SERP features, and discloses the exact cost model ($0.002 USDC per successful call via x402 on Base, Solana or Arc) plus the fact that failed calls are not charged. That pricing and failure-billing detail is exactly the kind of behavior an agent needs before invoking a paid endpoint.

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?

Three sentences, front-loaded with what the tool returns, then limitations, then pricing. The payment sentence is the longest but carries decision-relevant cost information, so it earns its place; minor tightening (e.g., the parenthetical data-source note) would make it a 5.

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-value explanation is unnecessary, and the description covers scope, limitations and billing for a simple two-parameter tool. It does not mention latency, rate limits or what happens if the x402 payment fails mid-call, which are the remaining gaps for a paid external service.

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% — q and limit are both documented with ranges and a default — so the schema carries the parameter burden. The description adds only the indirect note that results are the first page Bing returns, which loosely contextualizes the limit ceiling of 30 but gives no ranking, freshness or result-quality semantics.

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: Bing web search results, returning title, URL and snippet in Bing's ranking order, and notes the data source (public RSS, no key). It is clearly distinguishable from the sibling news/vendor-specific search tools, but it never explicitly contrasts itself with the near-neighbor search_google_search or search_news_across_the_web.

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 implied rather than stated: the agent can infer this is the general web-search option among many vertical-specific searchers. The limitation clause ('first page only; no paging, no ad or SERP-feature data') implicitly tells the agent when this tool is insufficient, but no alternative is named for those cases and there is no explicit when-to-use statement.

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