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

Annotations already declare readOnly, openWorld, idempotent and non-destructive, so the safety profile is covered. The description adds genuine non-annotation context: the metered pricing (free samples then $0.003 USDC via x402) and the fact that only 'public' pages are supported, both of which affect whether and how the agent invokes it.

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?

Two sentences, front-loaded with what is returned and then the cost model, with no filler. The enumerated field list is somewhat long but readable and each item is informative.

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 re-explained, and annotations cover the safety profile. The description still adds the two things structured data does not convey: cost/x402 metering and the public-only scope. Only the absence of guidance relative to web__unfurl keeps it from a 5.

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?

There is a single parameter with 100% schema description coverage ('Public http(s) URL'), so the schema already carries the semantics. The description restates 'public web page' but adds no format, length, or edge-case detail beyond the schema, making the baseline 3 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?

The description names the resource and output form precisely ('main content of a public web page as clean markdown') and enumerates the returned fields, so an agent knows exactly what it gets. It does not explicitly distinguish itself from the nearby sibling web__unfurl, which likely also extracts page metadata, so sibling differentiation is left to inference.

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?

There is no explicit when-to-use or when-not statement, and no sibling is named as an alternative. The only guidance is the implicit cost model ('a few free samples a day, then $0.003 USDC per call'), which usefully signals this is a metered call but does not tell the agent when to prefer web__read over web__unfurl.

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