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

Goes well beyond the annotations, which only declare read-only/idempotent/open-world/destructive=false. The description discloses 1-hour caching with <5ms hits, the 5-free-call trial, per-call and cached pricing, that failed calls are never charged, and that the payment-required response is a quote rather than a fatal error. These are exactly the operational traits an agent needs and cannot get from structured fields.

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 core purpose in one sentence and uses labeled sections for routing and parameter interactions, which is easy to scan. The payment/pricing block is verbose and repeats the free-call and agd_pass_/tx_hash guidance already implied elsewhere, so a little trimming is possible, but the density is justified for a paid tool.

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 an output schema present, return values need no explanation, and the description still covers everything an agent must know before calling: authentication/payment flow, caching, mode-dependent behavior, input limits, and failure semantics. Nothing required for correct invocation is missing.

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 baseline is 3, but the PARAMETER INTERACTIONS section adds cross-parameter meaning the per-field schema text does not consolidate: url is not fetched when html is supplied, and mode='markdown' silently ignores query and max_tokens while mode='budget' applies BM25 ranking. This prevents misconfiguration rather than merely restating field docs.

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 and resource ('Fetch a public HTTP(S) web page ... distill its main prose into clean Markdown') plus a quantified outcome (stripping 85-97% boilerplate). It explicitly differentiates itself from both siblings by naming recon_webpage_skeleton and extract_structured_data, so an agent can route without opening a 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?

Contains explicit WHEN TO USE and WHEN NOT TO USE sections that name the alternatives and the conditions selecting them: recon_webpage_skeleton for heading previews on unfamiliar pages, extract_structured_data for JSON-LD/tables/code, and an exclusion for PDFs, images, and login-walled pages. Nothing is left to inference.

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