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

Annotations only declare readOnly and openWorld, so the description's disclosure of a paid x402 flow at $0.009 USDC per call is genuine added value — it tells the agent a payment step may be required before calling. It still says nothing about rate limits, result caching, or freshness/latency.

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 short sentences, purpose front-loaded, then return shape, then trigger, then cost. No sentence is wasted, though 'for AI agents' is mild filler and the output-field list partly restates what the call obviously returns.

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 no output schema, the description usefully names the returned fields and discloses the payment requirement, which is enough to call this simple two-parameter tool correctly. The missing piece is differentiation from the many sibling search-style tools.

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 (query, limit) are already documented in the schema, including the default and max for limit. The description clarifies that the query should be natural language, which is a marginal add over the schema's 'Search query'.

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 ('Web search') and describes the output shape (title, url, snippet). It does not distinguish itself from close siblings such as serp, news, or research, so an agent cannot route between them from the description alone.

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?

'Use when you need fresh information from the live web' gives a clear positive trigger, but there are no when-not conditions and no named alternatives (serp, news, answer, research all overlap). The guidance is adequate but leaves overlap resolution to inference.

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