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

Beyond the readOnly/idempotent annotations, the description discloses meaningful operational behavior: no browser needed, ranked results plus synthesized answer, maxResults range and default, includeAnswer=false to skip the summary, per-call pricing, x-credit-token header for unlimited calls, and the free daily tier. It adds substantial context without contradicting annotations.

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?

The description is front-loaded with purpose and output, then covers parameter behavior, then pricing/auth details. It is somewhat dense around x402 billing, but every part contributes operational value for an agent deciding whether and how to call it.

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?

Given an output schema exists, the description adequately covers what the tool does, when to use it, what parameters control, what results look like, and the external requirements (pricing, header, free tier, no wallet). An agent has enough to select and invoke it correctly.

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 the baseline is 3, but the description goes further: it documents maxResults as 1..20 with default 5, explains includeAnswer=false skips the summary and returns only sources, and clarifies that query is required and produces the described output shape. This is genuinely additive 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?

The description opens with a concrete verb and resource: 'Search the live web from an agent that has no browser' and specifies the return shape (ranked sources with title, URL, snippet, relevance score, plus a synthesized one-paragraph answer). This clearly distinguishes the tool from the many crypto- and wallet-focused siblings in the list.

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?

The description gives a strong usage context: 'The step before reasoning about anything that happened after the model's training cutoff — prices, releases, incidents, docs.' It also notes no wallet or API key is required. However, it does not explicitly mention alternatives like web_extract or url_extract or state when not to use it, so it lacks explicit exclusion guidance.

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