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

With no annotations, the description carries the full burden and does so well: server-side fetch, SSRF guard with redirects re-validated, 10s timeout, 1MB cap, and an explicit x402 price ($0.005/call, USDC, eip155:8453). Security posture, resource limits, and cost are all disclosed—far beyond typical coverage.

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 core action and output, then the operational constraints. The marketing-flavored clause ('The reader pattern agents use to actually understand web pages') is softer than the rest but still hints at usage; overall tight and well ordered.

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 annotations or output schema, the description supplies purpose, output shape, safety, limits, and pricing—enough to invoke correctly. Minor gaps remain: behavior on non-HTML/PDF pages, whether JS is rendered, and what a truncated response looks like at maxChars.

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%, so url and maxChars are already documented in the schema, and the description adds no per-parameter semantics (e.g., truncation behavior when maxChars is hit). The '1MB cap' refers to a server limit, not to maxChars semantics. Baseline of 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?

Specific verb+resource: 'Fetch a web page server-side and convert it to clean markdown,' with concrete detail on what is kept (headings, links, lists, tables, text) and stripped (scripts, styles, boilerplate). This clearly separates it from data-extraction siblings like live_url_metadata or dev_pdf_to_text, which do not return readable page markdown.

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?

The line 'The reader pattern agents use to actually understand web pages' implies when to reach for it (full-content comprehension rather than metadata), but it never names an alternative or states an exclusion, despite the domain-overlapping sibling live_url_metadata. Usage is inferred rather than directed.

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