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

Annotations only cover the read-only/idempotent/non-destructive profile; the description adds substantial context beyond them: a $0.005 per-call price, the exact paid endpoint (GET /site/snapshot), the fact that the default return is a payment request rather than data, the need for an x402/MPP client, and the P0 bearer-key path that self-executes and deducts the price. It also discloses that malformed input is rejected pre-charge, which is a genuinely useful behavioral guarantee.

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?

Front-loaded with the trigger condition, then the payload, then the two payment paths and the pricing. Dense but every sentence carries operational weight; only the long inline key-purchase URL and the slightly stacked final clause cost it a point.

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?

For a one-parameter, no-output-schema tool, the description covers the full lifecycle: what is checked, what the default response is (a paid request), how to complete payment, what the premium key path changes, and that invalid input is refused before charging. Nothing an agent needs in order to invoke it correctly is missing.

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 100% – the url parameter already documents the https-root, host-only constraint and gives an example. The description says only 'for your input' and does not restate or expand the format rules, so it adds essentially nothing beyond structured data; 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 gives a specific verb and resource: a 'health and content snapshot of your own website', enumerating exactly what is inspected (HTTP status, final URL, TLS, server, robots.txt, sitemap, WordPress REST). The 'own website' scoping plus the WordPress-specific coverage implicitly separates it from siblings like domain_report or check_infra, but no sibling is actually named, so it falls short of full differentiation.

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?

Opens with an explicit trigger ('Use when you need a health and content snapshot of your own website') and adds a constraint that bad input is refused before any charge, plus the prerequisite of an x402/MPP client or a P0 access key. It never names an alternative tool or states when another sibling would be the better choice, so it stops short of the top band.

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