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

Goes well beyond the readOnly/openWorld annotations: anonymous use is sync-only with no JS or custom headers beyond Accept-Language, rate/daily-volume limited, and keyed use via X-Api-Key unlocks crawl/map/search/batch/job history. It also discloses the render_js=false + wait_config rejection ambiguity rule, which an agent must know to avoid malformed calls.

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 purpose, then capability, then mode, then auth caveats — a sensible information hierarchy with dense, high-value sentences. The main drag is the pricing link carrying utm tracking parameters, which is promotional rather than instructive.

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 tool with no output schema and a nested request object, the description covers access modes, failure/rejection conditions, and what an async call returns (a job ID). It does not describe the shape of the returned content (e.g., how multiple requested formats are surfaced), which is the one remaining gap.

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?

Top-level schema description coverage is 0%, so the description carries the load: it explains api_key's effect and transport (X-Api-Key header), render_js/wait_config interaction (wait_config auto-enables rendering, conflicting explicit false is rejected), and processing_mode's sync-vs-async return shape. It doesn't document the top-level parameter names explicitly, but the nested $defs carry unusually detailed field docs, so the gap is small.

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?

Opens with a specific verb+resource ('Extract content from a web page') and immediately enumerates the capability surface (HTML/Markdown output, JS rendering, proxy geo-targeting, custom headers, wait controls, sync vs async). The scope is unambiguous even without sibling tools to contrast against.

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 explicit selection rules: use render_js=true for JS-dependent pages, omit/null wait_config to keep the adaptive settle path, send {} or concrete values for explicit mode, and use async when you want a pollable job. It also names the alternative consumer of async results (the 'job' tool) and states the anonymous-vs-key tradeoff.

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