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

No annotations are provided, so the description carries the full behavioral burden. It usefully discloses a concrete cost ('1 credit per call'), which is real information beyond the schema, but omits permission/auth needs, whether JS-rendered pages are handled, rate limits, and failure behavior on non-HTML responses.

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 zero filler; the extraction scope is front-loaded and the cost caveat follows. Nothing is redundant with the title or name.

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 simple one-parameter read tool with no annotations and no output schema, the description covers what is extracted and the cost, but leaves the return shape (flat list vs. grouped per type), empty-result behavior, and page-fetch constraints unaddressed. Adequate but with clear gaps.

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% for the single 'url' parameter, so the schema already documents it as a public http(s) URL. The description adds no syntax, format, or constraint detail beyond the schema, which is the expected baseline for full-coverage schemas.

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 ('Scan a page') and resource, and enumerates exactly what it extracts (emails, phones, social profiles), which separates it from generic siblings like extract_links and extract_tables. It never names a sibling explicitly, so differentiation is achieved through the field list rather than routing.

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 when-to-use guidance, no statement of prerequisites, and no mention of alternatives such as extract_links, extract_content, or scrape_page, despite several overlapping siblings. Usage must be inferred entirely from the field enumeration.

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