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

The description adds genuinely non-schema behavior: a $0.05 USDC x402 charge, errors being free, and hard caps of 3 pages and 30 links. It also notes that leaked secrets are masked in output, which is valuable disclosure. 'Read-only' merely restates annotations, and it doesn't explain output shape, but with annotations already covering safety, this is above the bar.

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 compact parts — a bracketed pricing/error preamble, then a single dense sentence enumerating checks and limits. Nothing is repeated and the cost, which drives agent selection, is front-loaded.

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?

No output schema exists, so the description should say more about what the audit returns (pass/fail structure, score, per-check results), and it is silent on that. It also omits the free_site_check relationship and any timing expectations. Limits and pricing are well covered, but the tool is only partially self-sufficient.

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%: the single url parameter already documents the http(s)-only, non-IP, private-address-refused constraint and the example.com default. The description contributes no additional parameter-level detail (e.g., whether the 3-page limit is configurable), so the baseline 3 applies.

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 a specific verb-resource pair ('pre-launch website audit') and enumerates exactly what is checked: crawl depth, link count, meta/OG/canonical, headers, HTTPS, 404s, sitemap, and masked secret scanning. This is far more specific than the title alone. It does not, however, distinguish itself from the free_site_check sibling, which appears to overlap in scope.

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?

Usage is implied by 'pre-launch' and by the disclosed cost and crawl/link limits, so an agent can infer this is the deep, paid version. But there is no explicit when-to-use vs when-not guidance, and the existence of a free_site_check sibling makes the paid/free decision the single most important routing question — and it is left unaddressed.

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