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

Goes well beyond the annotations: discloses the 15-second network-settle wait, the public/no-login boundary, the failure-mode signal (EXTRACTION_EMPTY), pricing ($0.01/call via x402 USDC or card key, failed calls free), and explicitly explains why readOnlyHint is false (per-call charging). This directly resolves the only non-obvious annotation.

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-loads the differentiator (browser rendering vs. plain extract) in the first clause and keeps every subsequent sentence load-bearing (trigger condition, constraint, example, price). Slightly dense, and referring to the sibling as `/extract` rather than `extract` is a minor notation inconsistency, but there is no filler.

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 still conveys the return shape (page text in text/markdown/both) and the degraded case (empty shell avoided, EXTRACTION_EMPTY on failure). Combined with the usage trigger and billing note, an agent has everything needed to call this correctly versus `extract`.

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 the schema already documents all four parameters and the baseline is 3. The description adds value with a concrete worked example (url, format=markdown, maxChars=20000, section=main) that shows how the parameters combine in practice, though it adds no defaults or edge-case syntax beyond the schema.

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 capability (fetch a page and render it in a real browser before extracting) and explicitly contrasts it with the sibling `extract` tool, which it mirrors. An agent can tell exactly what this returns (page text/Markdown rather than an empty JS shell) 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 an explicit trigger condition: use it when `/extract` returns EXTRACTION_EMPTY or too little text for a page you can read in a browser. It also states the exclusion clearly — public pages only, no login — so the agent knows when not to call it.

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