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

Adds substantial context beyond the annotations: the source set, robots.txt compliance, the exact price ($0.03 USDC per call, x402 or prepaid credits), that it is excluded from the free trial, and that it silently upgrades to full-web search (and price) under a condition. These are real behavioral traits an agent must know before spending money.

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 the core action and outcome, then pricing and tier details. Nearly every sentence earns its place, though the promotional '★ One of our best tools' is filler that could be dropped.

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 need not be explained, yet the description still notes the answer, pages read, and all results. For a paid, open-world search tool, the pricing, source coverage, and upgrade behavior leave nothing material missing.

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 'q' and 'pages' are already fully documented in the schema. The description references reading 'the top ones' and returning 'pages read', which loosely maps to the pages parameter, but adds no syntax or format detail. Baseline 3 is correct.

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 chain (searches, reads, summarises) and resource (web pages, cited answer) in one call, and names the tier (open-sources) and underlying sources (Wikipedia, Hacker News, DuckDuckGo, Stack Overflow). It is clearly distinguishable from siblings like search, search-open, and docs-answer.

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?

Explicitly says when to use it (ask anything / research a topic) and routes the agent to the free alternative ('Try search-open free first'), plus states the paid-only condition and the auto-upgrade trigger when a premium index is connected. When-to-use, when-not, and the alternative are all present.

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