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

Goes well beyond the annotations (which only declare readOnly/openWorld/non-destructive) by disclosing the exact cost ($2 from prepaid credits), the billing boundaries (never charges a card, never starts auto-reload, failed fetches not billed), the data processors (Firecrawl and OpenAI), the privacy guarantee (no wallet keys or chat content sent, no URL history retained), and the balance precondition. This is the kind of cost and side-effect detail an agent needs before invoking a paid tool.

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?

Purpose and the 'what it is not' clause are front-loaded, followed by billing, privacy, and setup facts in dense, non-repetitive sentences. It is long but nearly every sentence carries a distinct constraint (cost, billing limits, processors, error path); only the stacked reference links add minor bulk.

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 steps in by naming the returned artifacts (observed tools, recommended tools, do-not-expose), and it covers cost, privacy, prerequisites, and failure handling. The only real gap is the undocumented `max_offers` parameter.

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 0%, so the description carries the full burden. It clarifies `url` ('the page to audit' and must be public HTTPS), but `max_offers` is never mentioned, leaving half the parameters undocumented anywhere. Partial compensation justifies a mid score rather than a high one.

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+resource+scope ('Evaluate one public HTTPS page URL for WebMCP readiness') and enumerates the outputs (observed tools, recommended tools, do-not-expose). It also explicitly fences off what it is not ('Not a generic HTTP client and not a third-party REST wrapper'), so an agent can distinguish it from any sibling without opening the schema.

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?

Gives clear preconditions (public HTTPS URL, prepaid wallet required) and an explicit recovery path: if balance is below $2 the tool errors and you call reload_credits. It does not state when not to reach for this over the credit siblings beyond that conditional, so it stops short of full routing guidance.

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