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

Annotations cover safety (readOnlyHint, destructiveHint=false, openWorldHint), but the description adds material behavior they cannot express: the exact cost ($0.01 USDC on Base via x402), the 25-URL cap, the field set returned, and the paid(402) verdict semantics. It does not clarify timeout behavior or whether checking a broken URL still charges, so it is strong but not exhaustive.

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 tight sentences with no filler, and the price/payment constraint is front-loaded before the capability list. Information density is high without becoming unparseable. Minor jargon stacking ("$0.01 USDC on Base via x402 (agent-audit)") slightly taxes first-pass comprehension.

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 carries the return-value burden and does so by naming the five result fields and the verdict taxonomy (ok/broken/paid(402)). Payment prerequisites and the discovery step are both covered. What is missing is error/pagination behavior for partially failed URL batches, which 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?

Schema description coverage is 50%: the payment parameter is well documented in the schema, while urls has only type/limits and no prose. The description partially compensates by stating the 25-URL ceiling and that omitting payment returns the payment requirements, which matches the schema note. It adds some meaning over the raw schema but leaves URL format expectations (e.g., absolute vs relative) unaddressed.

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 ("Checks up to 25 URLs") and enumerates exactly what it returns: status, final URL, redirects, latency, and verdict. It is clearly distinct from read_page and preview_page because link-health checking with a verdict is the stated output. Sibling differentiation is implicit rather than explicit, so it stops short of a 5.

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 one concrete usage instruction — "Call without payment to get the x402 requirements" — which correctly sequences the paid flow. However, it never says when to prefer check_links over read_page or preview_page, nor when bulk checking is appropriate versus a single-page fetch. Usage is implied by the output list, not spelled out against alternatives.

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